Don't take this wrong. I think you did a great job on the phone mount and I'm not meaning to be Mr. Negativity here, just The Devil's Advocate.
I don't know the environment in which you ride. Perhaps it's not an issue for you, but I've given this a lot of thought since it could be for me. If I crash in the boonies on the way home from work at night, it's gonna be a long time before somebody finds me. I'd hate to be injured and not have a phone at hand to be able to use to call for help.
If you crash, is your phone still gonna be there and in working order?
I always carry mine in an inside jacket pocket. That way if I get separated from the bike, the phone is still on me. Will it survive a crash there? I don't know, but it seems like the place where it's most likely to not sustain damage and where I might be able to find it if I'm partially incoherent.
Again, not criticizing your mount and the way you utilize it in any way, but having your phone preserved and accessible post-crash is something to think about if your life might depend on it.