"WEll, I rather doubt removal of the labia enhances sexual function/satisfication."

I didn't see anyone making that claim but I suspect you are inferring from the opinion that removal of the foreskin increases "ejaculatory latency time" whatever that is supposed to mean.

The foreskin and the labia are rich in nerve endings which promote sexual response so to say that the removal of either enhances sexual function/satisfaction is a specious argument at best.