I'm not sure if this is even possible, but for fashion and body-type's sake it would be neat if people could mix and match phenotypes.
Let people take elf male pheno torsos/legs/arms/etc, mix it with human female phenos, etc.
I can imagine it would be very janky, but I mean.... it isn't like we are strangers to clipping/jank for the sake of getting a look right.
Maybe at the least, let people change phenotypes in the rest menu? Maybe give humans access to elven phenotypes too (and vise-versa), so humans can go unhealthy skinny and elves can go exceedingly large.
Anyway- that's the spirit of the request. More customization options, allowing male and female phenos access to the opposite's arms/legs/hips/etc.