How accurate is the readout from note-off  ?

Is the scan out position on the key travel accurate to the effect ?

I think both of those things would depend on the input keyboard and how you've set the note-off velocity curve - but it would need somebody with deeper knowledge to give you a more detailed answer. I'm quite happy with the effect from my Roland FP-30, but the note-off curve does need to be set with care to avoid sounding as though the piano has defective dampers!

There is most definitely a point to the note-off feature, and this is what it simulates:
On an acoustic piano, if you play a note loudly and release the key quickly, it stops the sound cleanly (provided that the dampers are in good order). However, if you play a note loudly and release the key very gradually, you get a sort of flanging sound as the damper just touches the vibrating strings. And lots of subtle shades in between!

How accurate is the readout from note-off  ?

Is the scan out position on the key travel accurate to the effect ?

There is most definitely a point to the note-off feature, and this is what it simulates:
On an acoustic piano, if you play a note loudly and release the key quickly, it stops the sound cleanly (provided that the dampers are in good order). However, if you play a note loudly and release the key very gradually, you get a sort of flanging sound as the damper just touches the vibrating strings. And lots of subtle shades in between!

great, and I learnt something again. thanks

cheers