I know several guys that swear by low dose Masteron year round as part of their TRT. Side effects are a very individual thing. Personally, Masteron does nothing negative to my prostate. For others, it turns it into a grapefruit. If it’s a compound that causes problems for you, avoid it. If not, run it.
I know guys who use mast, primo or deca with their test. If you don't get any side effects I can see it being a good long term stack. I would have regular health checks if I done it.