I feel that gap closers and backflips should be designed so that they are either 1. on the GCD and do less damage than the first ability of your combo, or 2. off of the GCD and deal no damage. It sucks when stuff like tank gap closers deal damage and are off GCD, because that means you're incentivized to use them ASAP to get in extra damage, rather than saving them for mobility when you really need it.