I've installed my CR Touch and I'm having nothing but problems getting the bed level.
I'm setup for UBL with a 10x10 grid. My M851 is X-45.70 Y-5.86 Z-0.52.
I run the following sequence.
G28
M189 S60
G29 P1
G29 P3 ;First column fill
G29 P3
G29 P3
@BEDLEVELVISUALIZER
G29 T
The visual output is easyer to see the problem.

There is no way my bed is shaped like that. Plus if I move to one of the channels and do a G29 P4 to adjust it, it is always off. Probing multiple places doesn't give me a consistent offset, so I can't conclude that my Probe Offset is wrong.

Is there a test I can do on the CR Touch to validate it is working right?

This is very exciting. I got my Ender 3 a few weeks ago and was just thinking about getting a 3D Scanner. I can model things in CAD but this would be a game-changer for me.