I see. In this case I would take your clap on an audio track, apply reverb to it, record just the reverb, reverse it, stitch it to the clap sample and assign the resulting sample to a pad in groove agent one, which you can trigger from an instrument track.
You can’t compute a reverb tail ahead of the sample in real time, that would involve looking in the future which is something even computers can’t do in real time . I don’t see how you could achieve that with a reverb plugin on an insert.
As you noted, the main difficulty is that the reverse reverb needs to begin before the MIDI event (the clap).
Short of sending your computer thru a wormhole, you could duplicate the MIDI clap track (and it’s instrument too!) and move all its events a wee bit to the left. Then put a reverb on the dupe track/instrument, which has a “reverse” algorithm (ValhallaDSP can do this I think) and set it to 100% wet. You will need to tweak the position of your duplicate events so that the reverb ends just before the MIDI clap starts.
Doing it with audio instead will, however, give you better control and is easier…
Personally, I would bounce a bit of reverb to audio then reverse it and place copies of it just before the MIDI clap events.