I also came across this while testing out Seedvault recently. And also will not continue to use it.
When inserting USB stick, a notification sometimes showed from the profile that was created with the seedvault backup (while being on another profile), even though said profile was not supposed to run in background?! It seems to have elevated permissions, which makes sense for such an app.
I ended up changing the backup method to internal storage, to get rid of the notification when I insert USB stick.
But will just delete storage of the app too now, after reading this is fine to do.