Off topic: That's a cool idea for design. I can't do it on mine, but I'm assuming that's a rotator as well?
On Topic: I also use a 3D printed focuser, and I have similar issues with backlash, though usually it's pretty good about it. I'll put it on my list of things to look at doing. But I've been quite involved with a local makerspace lately, and that doesn't show signs of letting up.