Find starting point in dungeon. A* to every room. Rooms with a large distance (iter count) and with only one or two paths out (choke points, use graph to see edges) become potentials, every potential that is _far & narrow_ is flagged “enclave” with rewards increasing by distance to start.

This is one way to approach the problem. The other way is to do prefab rooms and when generating your dungeons, randomly select one or two prefab enclave rooms to throw into the shuffle. Shuffle the rooms and spread them out then connect hallways and such. This is the approach that Enter the Gungeon took.

Another approach is what @otikik describes. Tracing the walls buy assigning a value to the cells that can then be scored. Minesweeper style.