It's probably doable. I've done some harness retrofitting for an overhead console build and it was relatively straightforward. That was without any pinouts either, just manually figuring out where everything went.
If we could get an awesome pinout sheet for the 2020+ headunit like the one posted for the 14-19 one, that would make things super simple.
The one other challenge is figuring out part numbers for the various connectors. Easy if you have everything on hand, but 10x harder trying to do it from pictures alone. And I'm not going to spend $1k+ on a 2020 headunit just to find out one of the connectors is NLA or custom.