One thing to consider is that modern, rigid rims, especially when combined with more steel in the spokes - more or thicker spokes - is plenty strong enough that decent wheels should hold up until you crash or the brakes burn through the sides.

That means that any discussions of the relative merits of flange symmetry vs wider bracing is somewhat academic. It's not like either actually fails in practice anymore. Things get much more interesting with light rims and spokes which, even built as well as the materials allow, result in more flexible wheels where a high side load can take the rim beyond the point of no return.

If you ask builders from a few decades ago, you'll get stories of potato chipping (my preferred term because it's closer to the final shape than a taco) a wheel while stress relieving it, something that just doesn't happen anymore.