I'll let you all in on a little secret — the 16" MBP fits perfectly well in the the BookArc insert designed for the previous generation 15.4" version. It's a tad snug, but I actually kind of prefer it that way, based on how I employ the stand (fastened beneath the desk.) In comparison, the previous (i.e. correct) one now seems a bit wobbly. This is just an excuse for TwelveSouth to make more money on the backs of existing customers. I thought about buying a new one, but wisely chose to wait and I'm glad I did.
isn't this the setup that can cause battery swelling long term? the forum topic has a bunch of people with 2018 MPB swelling batteries who claim this is how they used their MPB. I put 760 cycles on my other MacBook with no issues and never used it in this mode. always off the battery
I've been using a BookArc for almost a decade. I run my rig professionally 10-12 hours a day and have yet to encounter a problem with any of the 13", 15.4" or 16" MBPs. There's also an argument to be made that placing the unit vertically (vs keeping it feet down) can help with heat dissipation; and also not running the internal display alongside an external can slightly improve graphic performance as the GPU isn't driving two screens.
Not to discount other users' experiences here, but take with a grain of salt any issues involving the 2016-18 MacBook Pro. There are so many problems with that model — not the least of which is severe overheating and consequent thermal throttling — it's impossible to consider them fully representative of the entire MBP product line. And that is particularly true of the 6-core i9 variant, which gets hotter that Satans b***sack, and which most of the posts in that forum reference.
Anyway, Apple, per their own documentation, fully supports using the MPB in clamshell mode and has for as far back as I can remember, so it strikes me as doubtful that they would simply ignore an issue of this severity and send users along their merry way to the land of exploding batteries.