IMHO...

Any mesh for Poser should be mapped always... mapped and grouped being best. A map would allow a false catch light highlight for stylized renders. I do z-toon and ambient only "no light" renders for nice illustrative and painterly effects and don't always want to set up the whole reverse scene for a raytraced corneal reflection anyway.

Also, I have never seen transmapped eyelashes that compare to any of the pure geometric lashes even the Yamato's for Posette pre-Y2K... density can be controled by morph along with length and curl. I use conforming prop eyelashes on all but the Millenium 4 and that is because I just don't have them and haven't modified any from the older figures to fit. I double them up for density.

The layered eyebrows don't work for me but that isn't important... my personal preference would be that they be a sepearate body part if possible so they don't get in the way of headmorphs. No one ever seems to use transmapped textures for eyebrow geometries, I have not since the two layer eyebrows for Posette Eve, but the idea of a purely procedural skin including lips and eyebrows is intreging... I have tried lips and irises but never eyebrows.

If you do the brow maybe also a couple crinkly layers for pubic hair and armpit hair? I use iether geometric hair or transmapped  for that depending on the scene resolution but I figure most people prefer transmapped.

The last thing I would ask for is precise scale ratios between different parts as that would help with both textures and procedurals... knowing that the face texture resolution was 4x the torso texture for instance would help bridging the neck seam...

Thanks :)