Speaking as someone with zero actual domain knowledge, my concern would be about ensuring that disparate extensions have consistent interfaces and can cooperate

Speaking as someone with zero actual domain knowledge, my concern would be about ensuring that disparate extensions have consistent interfaces and can cooperate with each other. I don't know how that would work at a hardware design level, but the thing to avoid would be whatever is the analogue of the rust/async fiasco, where certain components only really work properly with others within their own "sub" ecosystem.