I have never used this function on all my Androids. What does it actually do? How do you view sd card contents if it's encrypted? Is it encrypted only when you remove it & view in other phone?
I'm weary of doing that to be honest, as if you do and your device crashes, you lose all content irretrievably.
There are cases where the phone didn't see the SD card after an update!
If you go down that road, just keep backing up the files on the card to a pc ermtc..
I do have mine encrypted. The older I get the more I have begun to value my privacy...I only keep photos/videos/movies, etc on my SD card...but I still don't want someone else to retrieve its contents...I have everything backed up, so I won't truly lose much.