Phantom
Im my best James Earl Jones "Vader" voice...Impressive!!!

ODF
I know wings3D and blender will use hard/soft edges but for poser you have to bevel things a bit to keep hard edges ( because of the the way poser smooths things ) AFAIK. Im probably misunderstanding what you're talking about here. Are you worried about harder edges not transfering over from low to high-res? Possibly making morphs alot different from low to high-res? If that's what your talking about I don't think it will matter too much.

I will probably only do morphs for the higher res one. I want to make some general shaping morphs for specific regions like hips-x, nose-y, and some FBM's such as BodyFat etc. Just general morphs that combine and reverse well, but I would also like to make a few very defined ( not necessarily muscular etc. )  complete character morphs that sort of stand alone and don't reverse or mix as well with other defined characters but still mix with the general shaping morphs and I know the low-res one will not support the defined morphs much, so Im thinking I may just do morphs for the higher-res one. Did that make sense? Lol.

Cheers,
JB