Hey! I had some similar thoughts and I tried them out! You're on to something. As au8ust mentioned, we're thinking of Synchro Focus. It's been done and it's just a matter of figuring out gear ratios generally. I went a route that is simpler in a way. With some measurements and an online calculator I found a perfect lens pairing for my Kowa Vidoscope Super-16mm 2X attachment for an instant Synchro Focus setup (I didn't need to synchronize anything - just had to connect them together in the right way hehe).
https://www.dpreview.com/forums/thread/4640463#forum-post-66072400
