Since there are far more restricted cards in Vintage than the current 30-card limit, and plenty of the cards banned in Legacy are strong enough in this pseudo-limited environment that they should probably be dungeon treasures too.

(Ideally, the 30-card limit should be increased, and either more treasures added to each dungeon or more dungeons added; but each of those three clauses are difficult.)

As a stopgap measure, perhaps make the list of dungeon treasures configurable in Shandalar.ini. This won't be difficult, though I have no idea what the effects would be if a game is saved with one dungeon treasure configuration and then loaded with another.