I don't see the issue... And I would expect the least complaint from the Americans...
A reminder from your own Bill of Rights:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
It's the FIRST one!
If this guy wants to wear a pasta sieve or any other kitchen implement on the top of his head, that's no different to a Jew wearing a yarmulke or a Muslim wearing a Taqiyah, let alone what all the other non-Abrahamic religions choose to wear...
The FSM group make a very important point that people of faith never seem to grasp; there have been thousands of Gods all around the World throughout recorded history, and those of the Abrahamic faiths reject all but one of them, while 'non-believers' simply reject one more God than 'believers' do.
There is no reason why any church of any denomination deserves any kind of tax incentive when it trades spirituality for dollars. However, if one does, then they all do.