I posted a game using outside box and one before.
(46457876). I am not sure about this but the computation for the fifth defender is something like OD + ID + SB so in this case, my PF guarded my opponent's outside scorer instead of my PG.
This is supported by the fact that my C (I think?) was chosen to be the fifth man for this game
(43161566).
So my advice is to try it yourself first in scrimmages before testing it in games that count.