Its mandatory (for me) to have a quick escape from many functions.
So in PS its possible to hit "escape" on the keyboard and the actual transformation/funtion is gone.
But not so in affinity photo. :-(
Edit: Its built in Filter/Distort/Perspective (translated from the german version), but its not in some other essentials like the named crop-function, mesh-transformation.
Please build this nice little feature in all/most functions for the next release. Thank you!