Thanks for this great job!
Dunno if it is an expected behavior or not, but when I enter the menu, the gui is updated once after the first keypress, and then is not updated at all then until the menu is left. Then all missed frames are caught up when leaving the menu. This gives a weird feeling with graphs being updated extremely fast.
I am running debian stretch.
Thanks Guinness! Gotta swap over to my day job but I'll try to circle back to look into the menus in a day or two. I definitely noticed some annoying issues there.