The current delay parameters on the xy-pad are not so usefull (for me). I would love to have delay time on the x-axe, and feedback on the y-axe, for me that seems a more usefull approach of the xy-pad.

Even better would be to select which params you would like to control on the xy-pads (for delay, and for reverb, although i find the default reverb ones very usefull). This setting is saved with the project.