I prefer to play with bars hidden, but this can make the UI seem less responsive without a visual indicator for the game registering an input. NugKeyFeedback is an addon available on classic that addresses that.
https://www.curseforge.com/wow/addons/nugkeyfeedback
Is there any working backport for 335? or some equivalent?
If there isn't yet then I suggest that this is a worthy target for backporters or anyone who wants to try here
