BTW, weightmapping is good. Very, very good. I wouldn't want to be without it.

BUT...some late 4th generation DAZ figures bend ALMOST as well just using conventional falloff zones.

That means that, while the weightmap still is better in general (Although not perfect), a really well rigged sphere/capsule rigged joint can easily be brought up to the same standard by an additional JCM.

I usually focus on improving already existing (realistic) figures, so I have not much need for geometry swapping.

And I usually weightmap male figures with their genitals intact and just add a "genital gone" morph. (Ouch!)  ;-)

But if I wanted to design a custom figure WITH geometry swapping, I'd just add a secondary hip like mentioned before, or keep the hip non-weightmapped and improve the joints associated with the hip using "stronger" JCM's.