When doing a drive-on trailer loading, with outboards, what is the rule of
thumb as how much to tilt the engine up? I see different amounts of tilt
used.

I know we lose thrust the higher up the engine is tilted. Maybe there's
enough to work with, even with the engine all the way up, though. Is this
the case? If so, guess it makes sense to run it tilted all the way up for
loading.

Is the only reason to bring the engine up at all just so your lower unit
might not hit the ramp in the process of getting the boat on the trailer?