I suspect it again comes down to what the iron is intended for Mike. If the camber is used to square joint the edge of a board then it's got to pay to use a profile that deliveres a predictable response in terms of change of slope/angle/inclination to moving the plane over towards one or other side of the blade. Rounded corners will obviously not be very useful for that, but they do seem to be a very valid option for smoothing.

There may be subtler considerations, but with a scrub plane it's maybe about coming up with the profile that removes the greatest volume of wood for the least effort - while leaving a surface that's a decent starting point for flattening and smoothing afterwards. e.g. no deep or inconsistent gouging or splintering.

I guess there's a lot to be said for a profile using a standard radius that can be applied using a simple holding device that rotates about a point. A CBN wheel though given that it cuts so fast should as you say though make it very feasible to using a honing guide or something to maintain the bevel angle grind back to a marked line to create a custom profile if needed - maybe even (if we're to speak very hypothetically/experimentally) with enough creativity in the set up one that includes concave sections ground off a corner of the wheel.

I've no idea though how unusual profiles like this might perform though...