This part has been designed after I built my chinese Tronxy X3 printer. I saw that the bed is moving in different directions much more than I would consider acceptable. So this part makes the bed really stable and not clumsy.
Easy print. Took about one hour all necessary parts in one print. 2x the main bed addon + 4x spacer which I printed to be sure, that they are the same length. May be necessary to drill the holes after, if your printer overextrudes a bit for easier assembly.
I used fusion 360 and blender to correct rotation.