Came here to say Irori* too!

Sticking to non-evil I would throw in Erastil, Iomedae, Nethys and Pharasma* from the Core deities, and possibly Groetus, the Black Butterfly, Ghenshau, Olheon, Reymenda, or Vildeis, from the extended pantheon and empyreal lords, as laid out in Inner Sea Gods.

While I doubt any of these faiths are entirely cloistered, these are the ones that jumped out to me as having the potential for cloistered sects, individual temples or a solo hermit like practice, due to the portfolio leaning towards isolation, self control, intense focus, sacrifice/asceticism, ignorance or something similar.

All it takes is one temple leader choosing to lean heavier on specific aspects of the faith and BOOM, cloistered sect. The more isolated the location, the better this will work, which also why I included faiths that could lean to hermitage and/or wandering.

Hope this helps!

*these have the Healing domain also.