never tried Radium, but in Apple's Logic Pro you can write Javascript to do stuff to the MIDI as it comes in or goes out. I've found it quite useful. I once wrote a small script (at the request of another Logic user) that turned a monosynth that only supported "low note priority" into "last note priority." I'd be interested to see what Radium can do.
Cakewalk has been scripted with a LISP (CAL) from the early days, at least through the 90s. I see hints that it still is but not sure with all the changes from Bandlab.