If I am doing a Planetary Square for a problem, am I also allowed to try to contact a demon about the same issue? Or should I finish the square first (some days in the future), then---if necessary---turn to the demon?
You can do this at the start, or when you feel this internally, start, middle, at the end. Yes it is very good to do this, your working will be manifested more powerfully and you will receive proper paths for the working.