This is a pretty simple suggestion but it would make life a bit easier. If you wanna add something to marktplace you press on , after that it will showes a new window:
Each time you open that window it will show the category even if you choosed a item from a different category before.
My suggestion would be to remember the last selected category. As example you want to add a few themes, it is kinda annoying to always select the
category just because it switch back to . So you open that menu for the first time and it showes .
Now you select and you add your Theme to the Marktplace. If you want to add the next Theme you open the menu and it already showes you
the category.