z axis depth indicator for QU-BD One Up and Two Up printers

Hey there. I came up with this thing to quickly checking the level-ness of my print bed. I actually leave it on the x-axis gantry to check the height before each print. To check the whole bed, I:

lower the hot end to 10mm from plate,
snap on the indicator to check front left and right corner (the spring holder tab serves as a lever for release the clamping pressure)
move the bed forward
check the back left and right corner.
If I leave it on the machine (right side of x-axis) I lose a