I’m slowly getting to the point where I have something usable.
I added a hose clamp, and magnets to install/remove the dust shoe easily (just like sliding the dust shoe in the Suckit arms allowed, but without the X travel penalty now):
Now that the design is semi-final, I’ll probably do a few final design changes and reprint all parts, to not have 4 different colors in this thing (which happened because I ran out of black PLA…)