I believe these mockups explain my idea very well. ^^
The main idea behind XY control is to easily modulate two parameters of (a) certain filter(s). XY controllers are found in plenty other DAW’s, synths, etc. In my opinion very useful and a fun way to play with parameters…sliders are boring. And it’s great for live or jam occasions.
About the terms I used:
“Time” could also be called differently; like ‘speed’ or ‘delay’…
Also, you could put the “Time” in milliseconds, or maybe it would be better if you’d put it in Lines or something…