Do you want the background to have looped back to the start after one cycle? If so, you probably have to make it repeat N times more than the foreground, and move by a factor of 1/N in comparison to the foreground. Or put another way, have 1/N times the length. That means that after one cycle, the background has moved a distance of 1/N, but also repeated exactly once.
I hope this makes sense...
I'm of course only one single anecdotal sample, but the release cadence has probably been the least of my problems. My experience is that it's fine to not update for quite some time. I have a crate with 1.60 (released about one and a half years ago) as MSRV, which means I run unit tests with that version, as well as stable, beta and nightly. The only pressure to upgrade is that some dependencies are starting to move on. Not that the newer compilers reject my code, not even anything deprecated.
Also, small, frequent releases usually takes away a lot of the drama around upgrading, in my experience. Not the opposite. A handful of changes are easier to deal with than a whole boatload. Both for the one releasing and for the users.