Very fast modulation speeds in Falcon are possible: you can go into the 1000 Hz range with the multi envelope (and draw strange, multi-segment LFO shapes as well), just zoom in really close to edit your shape and set the loop length, then you can also apply modulation to the speed with e.g. key follow or linear key follow, the latter set to 50% (or better 0.501) will result in chromatic changes of multi envelope speed.