well, 5 degs is better than 0 degs,
but who knows if it will work-have to try it and see....or go up a notch on the cruise fuel.
sometimes, more can be better
I have found that many cars of this generation cruise best around 13.5-1 because fuel distribution is not as even as with port injection. All it takes is one lean cylinder to get a little rattle.
I don't recall what you said about AF so you may be there already