When is the Best Time to Trim Portable USB SSD Backup Drives and How Often?

I have two Samsung Portable SSD T7 drives. I use them as backup drives for my PC drives/partitions. I use FreeFileSync for this purpose. I am aware that I would need to have Windows trim these portable drives from time to time. So how often should the trims be done? After every backup routine? Before every backup routine? Or some other scheme?

Additionally, when is the best time to do the trims? Is it best to trim the drives before making backups or after making the backups?

Lastly, does doing trims of SSD wear the drives down more quickly? I suppose I'm thinking that trims might involve lots of writing to the drives and hence that reduces a drive's longevity over time.

i believe that this maybe of use. its Samsung's own software for drive health and trim.

best of luck, Steve ..

Trim reduces unnecessary write operations and marks unused blocks for deletion, prevents slowdowns and minimises wear on the drive.
I trim externals when I remember

Backups are not affected by TRIM operations, because the untrimmed data is hidden from Windows' view and only visible to the SSD's onboard controller.

A host only sees a logical representation of the SSD's data blocks. Logical block 0 is probably not stored at physical block 0. Due to wear-leveling routines that help prevent excessive writes from lowering a SSD's lifetime, the onboard controller ultimately decides where data actually lives.

If there are SSD blocks waiting to be trimmed, they're not reported to Windows. And since they're hidden at the volume level, your backup software doesn't see them and no attempt will be made to copy the untrimmed blocks. It won't speed up or slow down the backup software's normal operation.

The vendor's special SSD software, like Samsung MAGICIAN, can talk directly to the controller and arrange special requests like to run a TRIM command immediately or schedule it.

External drives are rarely used for heavy writing operations unlike OS drives that can have same memory cells overwritten many times.

Trimming is only going to have very minimal impact on drive performance for external usb drives.

I only trim them a few times a year like @Fabler2 when I remember.

TBH unless drive is really full, I doubt the impact of trimming would be noticeable.