I have worked on the wgit ent plugin,i am searching, i didn't finished the plugin, i have 90% of values named, there are a lot of bitmask for transitions effects which i am looking for and naming. I will release the mainmenu skin+plugi+tutorial soon.
I can change text color/font(which must be already in the game)
Displace texts,buttons,bitmaps
Change the button type, show or hide a number of buttons
Change transitions or effects.
Duplicate or add bitmaps or text.
But i cannot add new bitmap tags to mainmenu because it brakes the external bitmaps for MP maps which are referenced on mainmenu

so for makign this new UI i can only use the existing bitmap tags.