Thanks for feedback. two main things:
1) Do you think I should add this "Materials are kept with udim" feature into official 3D-Coat release?
2) about UV / RETOPO ROOM. Many has asked this feature that users could see all tiles in uvmap at once. I think it would be nice but I also think that there is maybe other ways to implement this. Vision what I have is that you could select two (udim)tiles side by side and then move uv islands between them. If you have like 20 tiles in udim, navigation/moving island could become quite confused prosess if you see them in one uv map.
3) Other idea I have is that you could rename udims(1001,1002...) into names as you wish. For example rename 1001 into "Armor/Metal". Under the hood 3D-coat would still use numbered tiles but names would be only users eyes only.
fixed again some udim bugs from applink.