yet another bed level thing for delta

print at least first layer 0.1 or 0.2mm and hold up to the light to see hi and low patches
If your slicer allows, drop the obejct 1mm below the bed to only print the hex blocks

hexagonal blocks are 5mm or 10mm high and either 5, 10 or 20mm between flat sides.
The distance between different blocks (flat side to parallel flat side, outer or inner) is now always a whole number, tho this varies according to hex size chosen)

The largest flat hex is 95mm radius to the points, but may require