While I think this is the meaningful use case, that also puts a MUCH larger burden of "this needs to be 300% correct" to the project as a likely significant per

While I think this is the meaningful use case, that also puts a MUCH larger burden of "this needs to be 300% correct" to the project as a likely significant percentage of those legacy applications work BECAUSE of bugs and idiosyncrasies of that specific version of windows. Whereas the easier target of "emulation", such as with DOSBox and WINE, can get away with a lot more.