Ah, I see (you posted while I was typing) what you are saying.

The thing (in the past P7 has kind of overcome this issue) with Poser is that when you load in a huge texture, it crashes.  A bunch of 4096X4096 textures would send Poser 6 and lower into a nose dive.

So, texture real estate in the Poser world is very valuable.  A 2048X2048 texture that has only a face on it is much more valuable to Poser users.  It uses less resources, but gives a higher resolution then a 4096X4096 that has every body part on it.

We need (or desire) high resolution for faces and hands, but not so much for knees and elbows.  That's why the body can be on a separate map for us.  Am I making sense?

Your template layout there would have to be a lot huger then Poser's resources could handle to give the same pixel width on the face alone.

Well, I hope this makes sense.

Cheers!