We probably won't know until we try it. Usually because programming is done best through distinct logical systems (functions, objects, breaking up project files by what system they govern, etc.), the whole program (both how its different parts work together and how its parts function individually) is difficult to perceive all at once. It's much, much easier to just test compatibility between already written programs to see where they break then to try to prevent breaks before you test.
(Although, the best way to prevent the issues is to write one program with the other one in mind, but this is not the case for either windows 10 or FSO.)
That said, FSO has some really good people coding and they should be able to eliminate issues should they come.
