I don't think so. I wouldn't want to be seen anywhere on the premises of a Westboro Baptist function even if the building was closed and everybody had gone home. Such is my repugnance and abhorrence for what they stand for; what they do. And I would think it criminal if a gay person was required by law to be there, be seen there, to participate in an event there, before it starts, during it, or taking everything down afterward.
I assume you don't include government employees in that, let me know if I'm wrong.
That is a side which does need to be seen. If a gay marriage is a protected event, then so is a Westboro event. An African-American caterer cannot refuse to cater a KKK rally. This is about equal protection, not special protection. At the same time, we have the issue of state rights. If it is a valid right of the state to make discrimination illegal, where is the end of that right? For DBlack, that is simple. He thinks the state does not have the right at all. But for those of us who think it does, how far does it go? Personally, I think there is no limit - at least in terms of things open to the public. I see nothing in the Constitution which creates a limit.
But let me turn it around to explore this further. For those who think the florist is wrong. If the florist was black and the event was a local chapter of the White Supremacists of America chapter, would she be in violation of that law for refusing service?