Many years ago, I had a 16ft Ouachita tin skiff with round chines. With just me and the dog on board, it was OK, in that I didn't notice any problems. With me, dog, another person and some gear on board....big difference. In a steep turn at speed, water would climb the side of the boat almost to the gunwale and you could feel the speed drop from the drag.
Much later I had an ancient 19 ft Glastron runabout with...sort of hard....chines and strips on the rear quarters similar to the pics on OP's post. Even with hard chines, you could see water start to climb the sides - until it hit those strips, then it was deflected out. The boat cornered beautifully and was very dry. Haha....styling was archaic early 1960's, but I grew to love that old boat. It served me very, very well for 700 hours in 6 years in some very rough going at times.