It would be nice to have “note replace” be default and “add note” while holding down the hold button.
And even nicer would be Sostenuto … while normal playing and/or with the ARP.
I buildt myself a little 120g heavy lead block with rubber feet for “mechanical” Sostenuto.
Called it my 11. finger … keeps the left hand free for tweaking the patch while one bass note plays continuously.
By the way, even a sustain pedal is not really as usefull as expected while playing with ARP on, because the synth engine playes (and holds) the notes outside of the ARP sequence that are currently pressed while taking the foot from sustain pedal .
Not sure if this is a bug or a feature…