Fullscreening just adjusts the tabs and GUIs to the same size, It still is oversized since 9.7, And if i switch back it most likely still will be.
I turned off clickable gui, But it's too late for that, After i posted it i deleted the tabs so i don't know how to get them back, (Should have thought twice)
But you should also make it so you can make a clickable and non-clickable (use arrowkeys) tabs, Probably make it easier for everyone (just a suggestion, I hope you also look into adjustable tab/gui sizes)