Trailer question

I have a 16ft Bonita with a 150 Merc on it. The trailer is a drive-on with 1
set of bunks and center rollers. Since getting it a few years ago, I have
always had trouble lining the boat up to drive it on. I have been noticing
other trailers similar to mine and noticed a lot of them have a second set
of shorter bunks on the outboard side and that looks like it would solve my
problems a lot. When I add them, should I adjust both sets of bunks so they
do not hit the rollers or just touch them? It seems to me I would be better
off if they didn't come in contact with the rollers so the bunks could
straighten the boat. All opinions appreciated.

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Bill
Chesapeake, Va