The screen I play on has a lot of pixels per inch, which means some sites have UI elements which appear very small for me. This is usually fine -- I can use Ctrl+ to browser-zoom and expand the UI to where it would be on a less-dense screen.
For oEtG, what I currently do is put the magnification at 150% and that let me put the game interface in a browser window which takes up part of the screen (not full-screen), scrolling the right-hand chat window off (outside the window's viewport), but allowing me to horizontally scroll back to it when I want. This gives me a comfortably-sized game view.
Today's UI changes break a bunch of stuff for me:
I can't scroll left all the way left when the browser view is magnified, and at 150% (comfortable size for most oEtG text and images) there are things lost to which I can't recover, such as the "Exit" button on the Library view.