HP have a 13.5 inch (same size) 3:2 (same aspect ratio) 3000x2000 resolution (higher), 400nit (fw is 400+ so maybe lower) 100% DCI-P3 (better) multitouch AMOLED display as an option HP Spectre x360 14.
I would pay a lot of money for that monitor option on a frame.work.
There is almost 0 chance of being able to swap out the screen panel for one not sold by framework though. Between sizing differences, different mounting points, different power requirements, the mostly proprietary data cables for touch signalling and the about 20 different spec’ed cables for eDP (video signal) it’s just not going to happen.