I’ve been known to misunderstand a lot of things… but what I’m saying is that it can’t be a problem with note-off per se unless every note you encounter results in a problem - since each of them sends a note-off when they end.
The all notes off at the beginning is just what it sounds like, but the VST of which I am aware are “sticky” in the sense that a key switch doesn’t go “off” just because you release a key (Note-off) - They stay where they are until they receive a new key switch somehow. That sounds like the reset Paul mentioned is being used, or your “normal” has one.
This you can’t do, unfortunately. I get it. Dorico doesn’t silently play all the previous notes (including key triggers) before it starts playing at an arbitrary point. If you get rid of the reset, It will stay in the last mode played (whether you want it too or not, sigh) but the sound would then depend on where you stopped.
Maybe the happiest option is to define a custom PT or two, something like “pd” or “pda” or whatever that invokes your key switches. Then you can temporarily insert the PT above any note or rest when you are working on a passage. I know its a workaround, but it seems a lot easier than entering or deleted a bunch of notes.
Keep or sweep as you wish.