Hey there. As a foreward, I’d just like to open with the fact that I’m a career UX Designer. As such, the following is considered a bug:
[- This character used a Character Boost too recently. Try again later.]
This is not a complaint of the system put in place in and of its-self, but rather the fact that there is no information regarding the amount of time a user has to wait on-screen. Nor is there any information or forewarning regarding this during the purchase process. The fact that this isn’t present in the user flow, is by definition a bug and as such is negligent on Blizzard’s behalf.
Suggestion: Simply chuck in there that you need to wait 72 hours from boosting a character, and include this information prior to confirming the purchase. Even if it’s put into a block if text or a few paragphs, so long as it’s there.
Cheers!