Service program signatures, and how to avoid unnecessarily recompiling programs that call service programs

O.k. I'm kind of hitting a saturation point wrt service programs.

One thing I want to be sure of is to avoid having to recompile programs
that call procedures in a service program unless absolutely necessary.
Early on in my testing, I ran into MCH4431 - Program signature violation:
Cause: The source program AR8554R specifies a signature
X'FCC376CD114571CD674FE1584C1D6429' which is not supported by service
program UT9800.
Recovery . . . : The service program interface has changed. Re-bind
source program AR8554R.
Since I was doing a lot of development work in both programs, I didn't
investigate what changed, especially since this is brand new development
and the service program is not yet being used in production. I just
recompiled AR8554R and went on my merry way.

I've learned that I should add new exports only/always to the end of an
existing export list in my binder source. My understanding is that, by
doing so, programs that call existing procedures in the binder source do
not need to be recompiled. Correct?

Also, if I change an existing procedure in a service program but do not
change the procedure interface, do I understand correctly that I won't need
to recompile any programs that call that procedure?

Is there a go-to reference for this topic?

- Dan