Well in the end I didn't do it. I got heavily distracted and realised i wont be able to return the 5500M if i've modified its insides, and have run out of time to return the 5600M as well, which will soon become my primary machine (not that I will use any others, including the 5500M).
Thus, my only real option is to send the 2019 model 5500M to Apple, hope they can repair it (assuming there is something to repair), and either get a replacement or the same one back and fixed - then sell or pass it on.
On that end, I have some questions. Some are of a highly speculative nature, so thoughts are appreciated with no expectation of relevant/insider knowledge or accuracy.
1) Should the 16" with Apple silicon come this year, and I wait till the refresh, and after it has happened and I return the 5500M, and Apple do agree to replace it for nearest like - what is that nearest like going to be? As this machine is maxed out, and if it is an Apple silicon machine it gets replaced with (i.e. the refresh is solely Apple ARM), it would have to be a pretty good machine replacing it, possibly maxed out too, so I'd be more than happy with that. If there is a non Apple ARM version during the refresh however, offered as part of the line up, I assume then that that would be nearest like - thus, what are the odds by then (end of this year) that it comes with a 5500M or 5600M? I should add that I have AppleCare.
2) I find that using any browser I find tolerable (i.e. Firefox with extensions/add-ons, or Safari with none) completely wrecks this machine if there's video or even a gif. It is better when integrated GPU is enabled, but not forever, and inevitably gets too much. Is this something wrong with the browsers or the machine?
3) I also think, having watched a few teardowns and conducting a couple other experiments, that the side fans do basically nothing for heat, and that the fan that does all the work is the one beneath the screen. What would be the least bulky and easiest to transport around accessory that I could use to prop the laptop up entirely, especially on bed? I was using a rectangular block of wood, but no grip. I then (not seriously, promise...) considered a long rubber dildo (is that actually the only thing of that shape [rectangular, not phallic] that has grip?). I now think something much smaller, literally coat or even jeans pocket size, would be best.
4) Is there alternatively perhaps something I could attach to each corner to raise the machine a half or even full cm?
5) I came to this machine from a 2017 (I think) 13" MBP without touchbar. And I have to say, despite how it looks and despite the size of the screen (reminds me of my favourite mac ever, 2007 17" MBP), I really hate it. The heat. The fans. The stupid touchbar (which I have disabled thanks to a change allowing it in big sur). The lack of SD card drive. The stupidly sharp edges where your wrists rest. The terrible battery life (I get only 3 hours max usually - is this normal?!). The keyboard is good, but I never had a machine with the problematic (butterfly?) one, so it seems the same to me. I've never used the fingerprint thing, and genuinely forgot I had it till I turned on the 5600M. Even the camera, which should be so simple to upgrade, is appalling - I am sure this machine is faulty, as the camera quality is so much lower than any previous HD mb camera i've had. I admit the speakers are good, but not on a bed, and not always full stop. The USB-C is fine I guess, obviously inconvenient with old tech (or cables) but less so than the lack of SD slot. So my question here is, why does no one complain about this machine? Or if they do, even in large numbers, why doesn't Apple do something?
I just hate how Apple gets away with this stuff now. The fact that thumbnails are often blurry (why!?) and have been across multiple OS versions; that syncing a device without cloud is basically futile and has been for 3-5 years, crippling many's use or even enjoyment of iphones ipads etc; that the method for rearranging icons on an iphone screen is utterly insane (can you imagine if to move a file on MacOS there was the considerable risk it would shoot off into a random space or desktop or folder, or worse, trying to move the file would inexplicably cause it to not only shoot to the desktop, but cause all other files to as well, even meaning the emptying and erasing of organisational folders); that you can buy an album on itunes off the front page when it's released and then realise later that you bought the clean version (why can't they show it's the clean version if they insist on having two versions); that the design of iOS and MacOS (and modern tech design in general to be fair, e.g. what happened to about:config in firefox?) gets more and more like a fisher price toy, everything larger and larger, and less and less information available at a glance, or options to change things (why can't i permanently disable live photos on iphone, or permanently stop the slow shutter feature from being auto), or even the menubar just gets more and more cluttered and dumbed down; having to enable 2FA to use the homepod; how fragile or poor the iwatches are (I had a 4th gen replaced twice, once because of a shower, the other because of its bad battery); how you can't see when a person in group imessage is typing; how mail threads email conversations that have doubled up and split or when previous emails have been deleted etc together even with that option turned off; how poor the notes app is for searching and filing, things out of chronological order in search or things taking forever to be re-filed with no quick way to do it, or the disconnect in features between the macos version and the ios version, or the lack of export to a folder or zip for offline storage; how terrible the controls of quicktime are, and how they could take their cue from vlc but don't; or their air max headphones with its terrible half naked case; or the fact that you can't combine two multi-stacks on ios into one; how holding the iphone 11 pro max comfortably with a right hand little finger supporting its weight at its base means you block the mic; or so on and so on. Most of these complaints are years old, and I have written to Apple, I have even emailed Tim Cook hoping someone reads it and agrees, and yet nothing gets better. The same faults (like that bloody thumbnail one) get carried over to the new OS, or instead of upgrading the OS Apple instead upgrades their firmware and tries to sell you a 512GB iphone for $$$ whilst knowing its offline sync (and the entire point of having that capacity drive) is crippled and doesn't work (photos not synced, photos synced twice, music missing, artwork missing). And somehow I nearly forgot this till now - the most egregious issue, in my opinion. How iTunes/Music can actually damage your files (how I do not know), meaning the last 14 seconds of the song will repeat itself at the end, or sometimes 28, or even 42 seconds; how it won't play MP3s, especially those encoded using Lame, sometimes for more than 20 seconds before skipping - as someone who has spent a superhuman amount of time and effort on their itunes library (not just adding music to it but tagging, artwork, ensuring the best sound quality) these issues to me are unforgiveable, and with a 50K+ song library almost certainly unfixable.
Anyway hell of a rant there, but I am just immensely frustrated with Apple. Granted I should have tried to get the 5500M fixed first, and I should have returned the 5600M before I ran out of time. So the potential waste of money is my fault as there were possible and actual solutions I didn't try or carry out. But the fact that so much is wrong with Apple products, whether hardware or software, all the entire time now - and I do admit that some of my complaints above are trivial at best, or possibly even a question of preference, but a lot of them too are huge issues - really makes me wonder if their staff use Apple products at all. How can there be 100s of people posting about these sorts of issues, for each issue, and most likely 10s of 1000s of people lurking with the same issues, and yet there not be someone who works at Apple who has the issue? Or is it really that even if an employee discovers said issue, unless it's related to their tiny niche of Apple they simply can't say anything? Does TC simply not use the stuff, or does he use it in such a limited way that he really sees none of this? Do they not read this forum (or that awful official Apple forum which never answers the actual question, as if the people who answer there either don't read properly or are simply bots) and think they should fix or at least improve this stuff?
Clearly still ranting, so will stop message. Anyone with answers to my numbered questions, or thoughts on my questions during the rants, more than welcome to reply. What I would rather not have though re the rants is someone telling me I'm using Apple products wrong, e.g. I should embrace the cloud, change how I hold my phone, should never put a MBP on a bed, 2FA is vital in today's age so stop rejecting it (and how hypocritical to yet also worry about privacy re the cloud), the large iphone drive is for taking video not adding files sideways, dont use your electronic watch in a shower, stupid. Also would rather not have someone tell me to use a different OS or ecosystem - we know there isn't really any competition. My point is though that Apple used to really give a proper care about "it just works". Why have they stopped? They've got the cash to pay for it.