This modification should make the all axis perpendicular to each other and the z-axis also should be more rigid.
Originally I planned to mill the z-plate. This version will came in the future, here I want to share a printable version.
This modification address the following issue and was discussed:
You do need:
The Spoolholder can be found here: https://www.thingiverse.com/thing:2537713
In advance:
Yes, there are some Z-Supports out there but they only made the Z-Axis more stiff but the do not eliminate the a twisted X/Y axis. And if your printer is twisted first then the prints are not really useable.
The author hasn't provided the model origin yet.