That looks a really nicely built frame so definitely following to see the progression.
Is it the mech itself or the hanger that's slightly out? Either way should be easy enough, can change the mech out for another of the same or re align the hanger. I am sure there are a few people here who can loan you a rear hanger alignment tool.
Keep up the good work as you have something really nice now but with a bit of tlc you will have something really special to ride.
Jamie