Uploaded torrents and permaseed storage

I have a TrueNAS box with one WD Ultrastar 12TB drive just for trackers.

It is half full right now with mostly my personal torrents that I have uploaded to many private trackers (music, films, etc...) and permaseed stuff from those trackers.

I'm looking to buy another 12TB drive and was wondering if I should mirror the existing one or expand the pool to 24TB. Here me out, I know more storage is better for ptracker stuff but most of the stuff I have uploaded to those trackers hasn't been downloaded many times (niche content) so if I loose the drive it's over.

What's your storage setup?