If anybody can make any business make or print whatever design they want, then nobody really has any freedom. It would be no different than forcing a Jewish-owned printing house to print “The Protocols Of The Elders of Zion” or “Mein Kampf.”
Here’s my honest statement, DO NOT EVER OFFER a fully customizable service in today’s world, offer a set menu of options for your given service in question, and FWIW, this is about a whole lot more than concerns about being asked to validate homosexuality as okay.