I have 3 different Reason installed on my system without problem.
BTW everyone is so enthusiastic and focused on the rack and happy that rewire is dead.
but let's not forget that if you have projects on the sequencer you need to export all the tracks in midi, reimport them on the daw of choice and point every single track (and any bus / aux etc.) to the right synth / effect / combinator etc.
I don't know how simple and fast it is to do all this when someone like me has thousands of projects in Reason.
Is not practical at all. I have tons of project in productions, some ready to publish with my label and some
still on progress.