Thanks for the info OP, but in case anyone did not want to wait for that shipping from Slovakia, I ordered these and they work beautifully:
https://www.ebay.com/itm/2020-Toyota-GR-Supra-3-0-Premium-New-Huf-TPMS-Sensor-Set-42607-WAA01-433-mhz/254365716869?hash=item3b3960d185:g:KkAAAOSwNrBZ-j7e...
Thank you for the write-up! For anyone else that got stuck, you can see the panel that must come out first before accessing the (2) T20 screws here in KillxPoint's pic:
It is held in by 3 clips, I used a prying tool to get the left two clips out first.
It feels so much more immersive driving...