If you have a mfi(4) device – in other words, a LSI MegaRAID SAS driver – you can now see/import/clear/etc. foreign configurations, thanks to this commit from Sascha Wildner, tested by Francois Tigeot, and originally from FreeBSD.
For the confused, ‘foreign’ means any disk hooked to a RAID controller that isn’t part of a configuration the RAID device already knows about. A replacement disk, or more worryingly, a good disk gone bad/unrecognizable. (I’ve had both.)