I know it won't change, but I would support it. I've seen plenty of forums with limits in the 120-150kb range whose users browse just fine on phones, so, theoretically, I'd say something about there would be nice. I'd imagine an even higher limit would do very little given the current page loading times on modern phones.
Of course you can decrease the file size of signatures and such, but it's simply not going to look as nice with animated signatures. I don't think this suggestion is necessary, but since I see no problems with it and only aesthetic benefits, you've got my vote.