actually with more icons on the screen the FPS gets even worse.
try to open your inventory while your framerate is a little below 60FPS you will notice at least a 5 - 10 FPS drop from the inventory alone (and there is nothing transparent).
The more items you have in the invenotry the worse it gets because it has to display even more icons.
...and it borders on pure crazyness if you think about it that Cryptic makes a big deal about Polygon Budgets on Starships while the User Interface is the worst FPS sucker in the whole game engine.
If i open the exchange the Frames drop more then on any 3D event in the game.