ravas wrote

Is the concept of full and short commands exclusively for the tab completion/hint feature?

I notice that if I input: o
and then press tab
the output is "offset, ortho"

ortho is from the action I added (ActionDrawLineOrthogonal).

However it says nothing about "os" (ActionSnapFree)...
I guess because it's a short command...

Therefore it seems like the reasoning would be to limit what appears when you press tab.
Maybe the idea is to avoid similar full commands when coding so that pressing tab will complete more often.
For example, if I switch "perp" to the full command instead of "ortho", then o will complete to offset.

It's an unusual design... as opposed to the classic auto-complete list that appears while typing.
It does have the benefit of not running a function with every keystroke, which is something I like.