Syncing (rather than just extracting) data from FamilySearch to RootsMagic

I have been successfully using RootsMagic, plus the tools at, to analyse a lot of FamilySearch Family Tree data related to my family history.
This has worked well, but the data I pulled into RootsMagic a few months ago is now very out of date.
This particular RM database is just used for this analysis, I am doing no editing in it at all.
The RM UI appears to know which people have changed in FS, though it’s not clear what it sees as the start point.
But there seems to be no option to just implement the changes without prompting (presumably it won’t spot additions, not clear what happens about deletions/merged duplicates).
Am I stuck with simply re-running the FS extract (over 50,000 entries, many hours) on a regular basis, or is there a better way?

That’s really the only way. Initiate it when you go to bed and hope that it completes successfully while you sleep. And of course, initiate it into a new and empty database and don’t delete the previous database you have downloaded until the new download is successful.

I usually just compare little bits of my production RM database against little bits of the current Family Tree - just a few people at a time. But I very much like the way you are going about your analysis. I may try it myself.