Really loving this idea/content and can't wait to bust down the doors.

My biggest worry is this stronghold may end up in The Black Shroud.
I'd really like to see something totally different from the other 3 strongholds, that is not another "outdoors" like area, but rather a magitek fortress where there are corridors, barracks, and battle stations to infiltrate.

What comes to mind are places like Kefka's Tower, Shinra Building, and Alexander(Ifrit?) Airship in FFXII.

But if not in 1.22, I just hope we'll see something like this in the near future.