Welcome aboard Ed !!
Bunks are fine for boats, its the rollers that seem to be bad.
Bunk type trailers are better used on launch sites that have gentle slopes that allow the boat to float off the trailer.
The use of rollers is usually for steep non - concrete ramps, and large tide swings - maybe like the kind you have in your neck of the woods.
So if the bunks are located under the stringers in the boat, you're golden.