What is the trick to properly transposing a tune specifically for Jazz Guitar or does it matter?
You can read the same notes or chords as the piano. No transposing needed.
A guitar part is written in concert pitch, but a guitar sounds an octave below what is written. In BIAB, you can adjust the Octave setting in Preferences, MIDI Channels. The guitarists I write for can read it either way, but they appreciate when I give them the music in the right register.
(I have the opposite problem for piccolo trumpet, which is written an octave below where it sounds.]