Hello,
one more cent, for cancelling double attacks caused by latency it's possible to crossfade unprocessed signal with processed decayed signal, and wouldn"t affect almost all kinds of guitar effects based on windowing, this trick even resolve artefacts caused by pitch-shifting. Then the latency would be reduced to direct monitoring.
Selon Marco Donnarumma devel@thesaddj.com:
that even the un-processed signal goes through Pd to avoid echos or comb filtering due to latency.