Do that long test on all the drives just to see where you’re at right now.
If a drive fails the long test, RMA if still available.
After that it would be good to schedule recurring SMART tests. Do so using Data Protection → Periodic S.M.A.R.T. Tests
For extra points, look into using something like the most excellent Multi-Report to help you keep tabs on the tests and if your SMART attributes are going up in a bad way. There have been a few issues with Multi-report in SCALE 24.10.1 specifically, but it’s developer joeschmuck has been hard at work resolving those and a new release is set to go stable in the near future. You can follow the development of the newest version in this thread.