Leveling Jack FDM Calibration

So this is V1 of my bed leveling/calibration tool. I call it the "Leveling Jack" because it looks like a union jack. The thing I wanted to do with this is to show outline and fill across multiple diagonals and sides of the bed. It might do with having a circle in the middle, up to you.

Your looking for:
Holes/gaps between lines = Move the bed up
Rough to the touch, Look scraped across bed = Move the bed down
Nice and smooth with no gaps = ready to print

Enjoy!