WOw if your a Noob t Python you did very well, perhaps you have coding skills. But you did really well. I just wanted more settings. PS why have you made 2 panels now its better 2 kep them in 1. Its confusing when they are divide into 2.
I dont get why you want such a big send button. Its break with the style of bleneder. looks weird.
PS what happens now in your version when nothing is selected? In the old version everything got exported. I added code so only visible items are exported, so hidden an layers OFF wont be exported.
The apply modifiers is also important! You get errors when you import your UVs back. I made a extra option for that part.
PS we should merge the code, though your GUI looks way different. BUt mine is compact cause it only shows OSX possiblities, on windows it will show more.
I dont think this panel will work in a pie menu. I hardly use pie menus and i dont think the num menu can be done. Thats why i added a pop window instead.