I just don't know what you are talking about here, I have been using ForceFins for at least 10 years know, have been doing surface swims sometimes in excess of a mile with full gear and never had that problem. Its a technique thing, not a problem for me to do. Not to mention that I know play u/w hockey in them, where a large portion of the time is spent moving about on the surface and I haven't even a faint of an issue with slap.
For fine point precision maneuvers- ie photog's FF are fantastic, specially in surge. I did a proof test with a friend a year to two back, the test was in a mild (just over 1 knot) current, the test was to put our noses about 2 inches from what we were looking at, then rotate from horizontal, to vertical, to horizontal on the other side (upside down) then rotate face down and rotate a helicopter style around it. Needless to say, as soon as his nose was no longer directly into the current he (Jets) was washed off the point.