people will tell you a lot of things but I doubt there's an unreasonable limit
someone a while ago had a gif animation that was like a minute long for an avatar so it's obviously kinda big
anyway, yours seems to work, but I have some advice. when you export it in GIMP, for the frame disposal option, choose the "replace" one rather than "cumulative"
and make sure "use above disposal for all frames" or whatever is selected, just to be safe
