Down The Rabbit-Hole of Jazz Articulations

I’m trying to wrap my brain around adding, say, a long fall to the end of a trumpet phrase and getting the proper keyswitch to activate for that specific ornament. I admit to having become hopelessly confused, and would appreciate any clarity you brilliant lot might provide.

Libraries all seem to handle these quite differently, so it will definitely depend on which one you are using. 1) What library are you using for trumpets? 2) Does this library contain a fall keyswitch? 3) When does the keyswitch have to occur to trigger the fall? Is it an On event, Off, have to be triggered while the note is sounding, etc.?