Looks great! I like the design, nice use of Igus bushings, and I really like how the screw fits in the tube.
The CUI encoders have an index pulse, and we have some firmware that is done but just needs to be reviewed and tested before being completely ready. You can subscribe to the relevant issue on github. With this feature you should be able to retrieve the calibration once you have let the drive “limp” over to the index pulse. You will still get some movement on startup, but it should not be sensitive to any load you may have that may interfere with calibration.
We do also have plans for supporting absolute encoders, but that is a while before we will get up and running.