> enthusiasts making custom motherboards and screen adapters for old-school (seven-row) ThinkPads

This. It baffles me that companies like System76 and Framework refuse to borrow from an existing successful solution like ThinkPad. I remember asking System76 representative over the phone about trackpoint; from time to time I revisit that one thread on Framework forums about trackpoint keyboard... No progress there.

The only explanation I have is that they obviously can't copy, but designing something like an old ThinkPad is intrinsically hard and costs way too much for a small company.

I don’t know about today but once upon a time those trackpoints were encumbered by patent issues.