Well, fortunately Scrivener has its own autosave. 
You might be interested in methods for streamlining that. I also wrote a bit more on that, in this forum thread. With two systems pointing their automatic backup folders at the same synced location, it’s very easy to switch devices with minimal risk. For swapping .zips, most of the complex problems of smart sync and all that are nullified.
Treat sync like a glorified floppy. It’s what it is best at.