adding a lfo device to the effects would be sweet… it would work like the trackautomation, you can select whatever parameter you want to modulate (i.e. VSTi automationdevice-parameter, or channel panning, or … )
if not already possible; the ability to link velocity with filter cutoff could be handy sometimes.
it could be done with an envelope: one axis would be cutoff, the other would be velocity. this way you have total control over the cutoff behaviour.
and last, not quite sure, but maybe it could be usable if the scaling of the vertical axis of the envelopes could be switched between linear and logarithmic.