There are some threads around that discuss the body switch but an example would be the hands on the old Poser 2 figures. Instead of finger posing there was a hand dial that just switched out geometry for different hand shapes. Some old props link the Victoria morphing Eyewear also used a geometry switch. I once set up Poser 4 Nude Woman to switch between the standard head and a head remapped to its own map. My experience with this stuff is that if you made a lo res figure with a geometry switch to a high res head, the morph channels on the .cr2 would work if the appropriate morphs were injected... I have switched head geometry by making a head prop and using "replace body part with prop" and when the morphs for the replacement head were injected  they worked fine.

People might ask why you need a low res body under clothes instead of just turning off the hidden body part's visibility but I find quite often the clothes leave gaps that must be filled. It isn't often practical to just turn off the chest/collars/arms etc.

I bet you would have a market with animators if you had a figure that could go long shot in lo-res and feature the same character in hi-res for close-ups and inserts. I just want lo and medium res so I can get more than two fully dressed figures in a scene.