Is it possible to make the previous sound stop as soon as I play another note? It would allow only one note to be played at a time, everytime I press a note, the previous one gets brought to 0 volume (respecting the VOL ENV RELEASE time) and so on. From my research, I discovered that "Exclusive class" would help me, I tried setting its value to 3 and it worked, however as soon as I played the next key, the previous one gets immediatly muted... it does not respect the release time. Any idea how I can fix that?
Also, is it possible to ignore the sustain pedal when "Exclusive class" is set to 3 so that the sound keeps playing untill the end of the sample no matter if the user already released the sustain pedal?
"Exclusive class" doesn't respect "release time". This setting is intended for use on percussion type instruments. Its task: to "immediately" mute the other note to which the same (group) number is assigned. Whether the assigned numbers is "1 to 127", the effect of this setting doesn't change.
What you asked for: It consists of changing your instrument's polyphony setting to MONO mode (soundfont interpreter's (synthesizer's) settings) This has nothing to do with soundfont. It is a MIDI function that the instrument can perform.