Not to be a stickler but avatars that are too big can't be loaded anyways, it defaults to that basic gray figure. o-o;
Also, I'm not sure if this was before or after your post, she already linked a quote of the limits on signatures and avatars.
That's true, but the avatars are being made for the event. I don't imagine a lot of people will try making it work on their profile before submitting. (More so since the profile setting incorrectly says 500Kb as the maximum.)
And perhaps I misread ShadwoArc's post. I could have swore it was just the signature being quoted there. My bad.
Sorry for the trouble.