I used your renderUV script and mixed with one of mine. Now the script count black pixel on the uv map, and drop a percentage of "wast uv space" depending on the wanted size of the map. result just below my code is perhaps not very optimised, but its working well on editpoly object just select an editObj and run the script…
will have a look regarding the undo stuff any suggestions for that? - another input box would not be so nice, maybe a micro button mode toggle? or the right click for a scale mode (1x,4x,8x). I have read somewhere that the scrollwheel can be accessed in maxscript using dotNet maybe that might give interesting options.…