TOPIC: Endless Loop Note Off

I can make a sample whereas a NOTE ON signal triggers (in essence) an endless loop.

Can a 2nd loop/sample/note send a NOTE OFF (or some other way) to stop the 1st note (better yet, a specified range)?

Another way to look at it: How to make a range of notes mimic the "monophonic" characteristic of the very first synthesizers?

In essence, I want to accompany myself with loops/beats without having to deal with some new, additional stuff.

Es posible?

An endless loop triggered by a key is not possible. I think you are talking about "sostenuto" that should be made at the MIDI level: this would be a feature of your keyboard that hold on key until you trigger another one.
In a soundfont you can however loop your samples and select the maximum release of around 100 seconds at the instrument level. You will need to set an exclusive class also, so that when a key is triggered the previous one (sharing the same exclusive class) is quickly muted.
www.polyphone-soundfonts.com/documentati...es/instrument-editor