I have applications installed using AUR scripts - and none of them requires a scheduled AUR check.
I am using applications like
- postman
- azuredatastudio
- microsoft edge
- microsoft sql-server
and probably some I have forgotten.
When I remember it or when the app itself makes me aware - I rebuild the application.
While it is sound and reasonable to keep your system up-to-date - it is not necessary to automatically check the repos with short intervals.
I have been touched by the update-fast-and-now virus and it took me a couple of years to recover.
My personal recommandation is to run a manual checkup once a week or so - that is sufficient - unless of course you know there is a specific issue that needs to be addressed.