Literally no vaguely usable RAID solution ties disks to ports. Not Intel fakeRAID, not LSI HW RAID, certainly not ZFS. (the list goes on, naturally)
As you'll have guessed, my RAID experience is pretty poor. I was driven to FreeNas by repeated mobo integrated HBA failures that I wasn't able to recover from. They were basically RAID controllers that sat on gaming motherboards - nothing industrial or useful about them really.
So today, I swopped two HDD's round in the trays at the front of my machine, and in doing so returned the repeatedly failing drive into the array. In doing so, I remembered there's something else to consider - my machine has the hot swappable drive trays at the front, which sits in front of one of those SATA plates, which acts as a middle man between the HDD and the sata cable. There's twelve trays at the front, so if I get the same errors, I'll also need to try a different tray.
However, I reinstated the drive this morning and took 8 hours to resilver. It's currently scrubbing and I've got a green light with no reported errors.
Somewhere along the line, one of the three mirrored USB boot devices died too. It's happened before, so I keep a couple of identical flash drives around just in case. This is now replaced and is currently being resilvered too.