I wondered about that myself when we built ours (from a kit).  Had a dickens of a time getting the bottom glassed.  We toyed with the idea of doing something as you suggest, but ended up doing it as designed and living with (1) fighting to get the glass over the ridges and (2) the significant wear along those ridges now that we've used her a few seasons.  Seems she'd be a happier boat sliding over beaches, mud, indoor/outdoor carpet (which we use a lot when shifting her about), truck beds, docks and such without those bottom laps.  I guess in the end we were afraid we'd weaken the joints, but I still wonder about it.

I notice that on the smaller Ultralight Dinghy there do not appear to be any laps where the bottom three strakes meet each other and the lowest one meets the bottom.  The angles appear less accute there, so maybe it's just that those joints are simply too broad to make laps work--she looks a bit flatter on the bottom and firmer in the bilges vs. her longer cousins.

Maybe John will weigh in on this one....

.....Michael