SYSES string is as follows
F0 00 20 3C 02 00 40 25 65 F7 for “hold function”
and
F0 00 20 3C 02 00 40 25 63 F7 for “release function”
The commands don’t seem to do anything.
I’ve tried many other of these undocumented SYSEX commands, both toggles and hold/release combo’s, and I’ve got those working fine. It’s only the “hold/release function” command that’s unresponsive.