Birch

Press F11 do display your current frame rate. It uses an average of your entire play session which you can not see. Your last game was just 1% below the cutoff which you would not be able to tell.

Hi birch welcome to RU! I just saw your question "How will I know if my framerate was too low in the future (after submitting a score)?", there's no set way. Hitting f11 can tell you what your fps is currently at you'd have to make a judgement call to weither it's low or not. Thanks.

It can sometimes. You have one score waiting. Plaque Attack. But it will be deleted because your frame rate was 94% and you have to maintain an average of 95 or higher for it to count to keep it fair. Scores that are waiting for review show up on the bottom of the score page and say "Processing...Check back in a few hours."