FCPX auto backups driving me nuts ... can I change the duration between auto backups?

You can’t adjust the backup time. It has a mind of its own embedded in the software. That said backups shouldn’t happen while you’re actually doing stuff. The should happen very quickly with you pause, even briefly.

There shouldn’t be any transcoding going on if you switched off background rendering and auto transcode for multicam. Analysis for stabilization is also self inflected and not controllable AFAIK.

Why your computer is beach balling is another matter. It shouldn’t unless the system is really pushed. Could post you an EtreCheck report with Full Disk Access just to see if anything jumps out?

Nothing stands out other than stuff that’s been migrated from older systems. I don’t see anything that would cause what you’re seeing.

Try creating a new admin user and see if it changes anything. Reboot. Trash your FCP settings. Keep background tasks open as well as Activity Monitor and see what’s happening when beachballs.

Try trashing the settings. You looked in the background tasks to see that’s what’s happening?

It’s a free download. Don’t need the paid version.

https://etrecheck.com

Just make sure it has full disk access. Copy the report in the application and paste it into the Additional Text button.

14.2.1 ain’t beta.

Run the report and see what it says.