I think it'd be lots more useful to have the ability to run Pure Data patches in Reaper. There's already a workaround for this, sort of, which allows you to run the patches as VSTs but it's about as friendly as stabbing yourself in the eye with a fork so I don't bother. Considering how similar Pure Data and Max are, and how many Max and Pure Data users there are already - I'm talking about people building their own patches for practical purposes, not for academic exercises - it'd leverage a pretty large existing user base. Cut into that Max for Live demographic a little maybe.