To help stabilize and control the z-axis I made a brace consisting of 3d printed parts and M8 thread (and nuts and washers). It helps but the M8 thread is still flexing so it may be better to use M10. I ended up welding m8 threads to a solid RVS kitchen grip rod that does not bend at all.

You need 2x 1m m8 thread

12x m8 nuts

2x m8 bolts 50mm

6x m8 washer

Assuming your bed is level. Put an digital protractor on it and zero. Set it on the z-strut. Turn nuts until 90 degrees and fix with the other nut on top. (you need to cut the thread to length to fit a socket on the top nut). I used this https://www.aliexpress.com/item/33047262368.html

The thin-version bottom brackets are designed to be put between bottom plate and machine and require drilling. A hole needs to be drilled to mount the bracket to the casing. Another hole needs to be drilled into the bottom plate to allow for the bolt-head to stick through. The benefit is that with these brackets/mount they don't have to come off when the bottom plate is removed.  See corresponding photo's.