Hi, apple's yearly OS upgrades are just that - updates - you are usually not reinstalling the OS when you update.It is frustrating, all my pre-Cook macs were rock solid in terms of OS stability.
I'm reinstalling OS every year, thanks to apple's yearly OS release cycle.
I'm software engineer, so I'm very sceptical about tech support. No malware, no incompatible/illegitimate/outdated software, no crackware or bloatware, in other words, nothing that runs in userspace should be able to crash the kernel or windowserver. Kernel guys know it, but you can't reach them through support channels. And even if I could, what should I tell them? I can't reproduce the issue, and there are no useful logs. Probably some obscure driver or hardware issue.
Contacting regular support will be a complete waste of time.
As for mbp 2016, my gf is reluctant about contacting support. It's obvious software problem, she hoped that one of the updates will fix it, but it just never happened.
You need to backup everything to time machine, delete the drive, and reinstall the os - are you sure you're a software engineer - forgive me but that's kinda basic 101 of computer maintenance that would happen with a pc or a mac.
If that doesn't fix it, do it all again, and this time reinstall each application one by one, until you have found the possible software conflict.
It is extremely unusual that your mac would not have generated a log crash report upon restart of the frozen machine. I've never heard of that happening before.
Agreed, regular tech support won't give you anything more than I just have, but unless I have misinterpreted your post it sounds like you haven't done fundamental trouble shooting yourself yet, so I'm confused why you don't think support would have been able to help you. If first tier apple support can't help, they will elevate it to second tier senior tech support. Unfortunately you are out of warranty so you won't get an automatic repair case, but if they can't help, they will usually escalate to cupertino.
If your girlfriend is reluctant to call apple support, then what is the point of complaining about how bad apple and their support is, if one is 'reluctant' to use that support in the first place. I am confused.
Best of luck