Did something change to allow any id or class matches to be targetted and not just turbo-frames ?
I’m convinced you used to get an error if you targetting anything other than a turbo-frame.
Am I going mad ? 
Yes.
Aaah thanks for spotting that - I did look 
I spent a fair amount of time adding my own extra actions to support similar functionality and then just happened to notice (as the result of an incorrect action) that the standard actions worked