You are not trying to find a "path" since you don't have a starting point - you only have end points. Your enclaves are more defined by the shape of the walls (roughly x cells in radius) than with the fact that you reach them through chokepoints. After all, a chokepoint can be just a small door in an otherwise big corridor, separating two big areas. And by concentrating on chokepoints you will lose all the "isolated islands".

You might be luckier treating this as a "map treatment" problem. An algorithm that does things to the whole map, and then reads the result.

For example:

  1. Start assigning a score of 0 to all map cells.
  2. For every cell in the map, set to 1 if it's in contact with any walls
  3. Then add 1 to every cell of the map if it contacts a cell with a non-zero value
  4. Repeat the above step n times, where n is the average "radius" of you enclave rooms.
  5. Every cell with a score of n or higher is a "candidate". For every candidate:
    5.a Check that none of the cells around have a bigger score. If so, move on to the next candidate
    5.b Check that there's no "treasure" around it in a circle of radius n
    5.c You have found the center of an enclave. Mark it with "treasure" and move on to the next cell.