In my non-producer terminology, you effectively want to apply a changing morph effect to the long plaits note which is only playing one event per cycle - but the problem is the morph value is only being taken/applied at the time of the event?
I think what you're looking for has been implemented in tidal as "control busses", but these are only available on a subset of effects (and these ugens are not one of them)... it would be interesting to know how/if the ugens/scsynth/superdirt defs could be modified to make them work though (any thoughts @yaxu )?
I did a demo with them and midi input here: