Created attachment 227536 [details]
Sorry, I stumbled across what _might_ be another minor issue.
After using gdisk options x, z to destroy GPT data structures and blank out the MBR, the recently fixed version of lsblk showed:
da0 0:196 466G freebsd-swap - SWAP
After switching off, then on, the multi-purpose dock in which the hard disk drive is seated, output was correct (the same disk, at da4):
da4 2:119 466G - - -
Can you repeat that please like that?
# sh -x ./lsblk da0