I have been experimenting with 8K textures a lot of time.

For Roxie I made a 16K to 4K texture, no problems. (Glued all existing color diffuse textures together horizontally)

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!