It can become dangerous if you unearth secrets and expose powerful people. It may also be dangerous if the ruler of your 12th house is at the same time heavenly aspected and undergoing a stressful transit. Otherwise, this progression should come with a lot of psychological insight into self and others. Good luck!
Progressed sun will have been in 12th house for many years if its NOW within 5' of Ascendant degree…
I have found that 12th house is THE most cadent/hidden progression going. I wouldn’t interpret it as if in 1st house yet and it SHOULD be noticeable 1' approaching Asc degree. So it should be a quiet time for reflection,working behind the scenes, maybe some charity work?
I AM curious though as to why you would think this progression dangerous??
learn secondary progressions