I haven't had any issues with double nostrils and septum but it is kind of annoying with certain jewelry... I find that if I wear regular nostril screws and have my septum flipped up they can get hooked on each other sometimes. Eventually I discovered tiny labret studs for nostrils and they are the most comfortable things ever!
I love the double nostrils/septum combination, you should definitely go for it!
I have 1/2" lobes and 11 piercings: left helix x2, both conches, both nostrils, septum, navel, and VCH.
My lobes are small but I know a lot about stretching and how to do it safely, so message me if you have any questions!