Just tried again, no it is not working. I'm referring to the Coarse in in the Tune area (most left window).
Once i turn off the granular engine, the modulation works as expected.
Added: modulation is not working when Dens and Density is set to zero.
I believe it's in the granular synthesis nature, that you can't bend the pitch of a playing grain, if that's what you mean.
You can fire grains away that each have it's own pitch, so to speak.
So modulating the Tune sections Course does'nt change the pitch of playing grains, but only the pitch that new grains is fired away with.
The current amplitude at any time of a LFO will affect the pitch the grains is fired away with. The reset source and the phase setting of the LFO will thus also have an impact.
The envelope start at the value 0, so you will not have any effect on the first grain, when the envelope is triggered. But if you in example try to set a long attack, decay and release and the sustain in the middle and let it modulate the Course, then you will hear, that each next grain fired away will have another pitch in all stages except the ones that is fired away in the sustain phase, as they all will have the pitch set by the sustain modulation.
It can be argued, that if the attack of the envelope is 0, then the set pitch for the first grain should be max level/ modulation. I guess this affect all envelopes attacks modulations. However the smallest attack time is 0.1 ms, and i guess a envelope is closed untill opened so to speak.
Don't forget you have Functions you can use as envelopes, if you wan't to affect the pitch set for the first grain. There the initial level can be set like you wish.