Make Strongholds a more dangerous trial chamber-style dungeon

I feel the infrastructure for Trial chambers can be used to make strongholds more interesting. They're currently a random mostly-empty structure with a portal to the final boss. Adding a combat element that leads up to the final boss could make the end game far more interesting.

You could potentially go further than that and give it unique mechanics with chambers with locking doors, and mining fatigue until the portal has been opened.