Re: Trailoring with outboard in verticle or tilt position
vertical is best if you have the clearance. Be sure to account for driveway humps.
If not, using the tilt latch is fine even though the manuals all say not to (just one of those overly cautious things--they also say not to work on the motor on the tilt latch). There are no known incidents of a tilt latch bending under the weight of a motor in transit.
If your transom needs saving from a tilted motor on the road, you need to fix your transom. Operating forces are way harder on it than trailering.
if you lower your motor onto the tilt latch with your PTT then it won't bounce. If you don't have PTT you can secure the motor tight against the latch with a strap.
The next best course of action, if you think your latch will mysteriously spring into action, wait for a 2" high bump and release itself just to be devilish, is to lower your motor onto a board, block of rubber, etc. up under the motor, and secure it. We used an old hammer handle. Tie it to a string so if it comes loose it won't hit the guy behind you.
Resting the motor on a block (or latch) transfers whatever motion there is to the transom and motor frame, which is designed for it. Your rear trailer strut is not. Further, the boat and motor move together but they do not move with the trailer. Thus the transom "saver" creates an unnatural twisting force at the motor's point of attachment on the tilt "hinge." And it's even sillier if you have to use one of those bent transom "savers" to reach up under the boat, which can't be strong enough to channel the forces directly to the strut--you know, that trailer part that isn't designed for such force and which is insiduously rusting out from the inside and growing weaker anyway.
The best place to put a transom saver is on the table at your next yard sale.