While not a big issue, I have just encountered my first Sampans since the new RFB tweaks. S-Boat out of Dutch Harbor, July 43, calm seas.
Achieved sinkings after 3-4 deck gun rounds into the hulls, 7-8 if topside hits. I think it's a much better balance between real life 'burning with no crew' and game engine 'only sinking counts' mechanics.