ill say it first, this is an absolutely terrible idea imo, it would cause this forum to become a cesspool of begging spam and would just make more work for the mods. "tip pls" "click tip me" "pls need $$$"
you think people complain a lot about signatures? imagine the complaints that would come against the tip button.
Well, tbh, that is pretty much as easy to do as asking for donations to your BTC address.
I don't think it would be spammed much if mods just ban them.
My main problem with this is that the messages would add more spam and that the changetip feature wouldn't be much different than addresses.
I don't see how begging for a tip would be different from begging for a tip and posting an address.