You know the transom savers most of us probably have used. The support arm that went from a raised lower unit to the trailer?
I'm sure it helps but it also transmits road vibration through engine and transom which isn't good especially with shock sensitive electronics on the dash and on the engine itself. A trailer not sprung right it would be a worse situation.
A better scenario would be lower unit to lower transom.
I hate little trailer tires. Give me a 15 or 16 inch wheel any day.
The problem though, if you have a trailer for light craft, say a kayak, maybe 2 kayaks, this may not be the ideal situation for that tire size in relationship to properly springing the trailer for that load.
It's the problem I see with taking a utility trailer and turning it into a kayak trailer.
Most are going to be sprung somewhere around a ton and carrying 200 pounds worth of yak and gear.
Everything gets transmitted to those yaks. The yak becomes the shock absorber. The energy eater.
I would say my ideal situation would be 25-50% above the weight of whatever my loaded boat weighed which would be much better than the 500% some people are running around with by re-purposing an existing trailer without respringing it.