Guess us yankees must be less self-reliant and need more watching.
I have seen one silnylon tent go up in seconds - reminded me of napalm - and also saw a couple of legal aid pals turn a Svea stove into a flame thrower, that went up about 12 feet. Luckily, we were in a metal roofed shelter, not a tent, and the shelter just got singed a bit. OK, they were from NY City, and may have got frustrated with the stove and kicked it around a bit. But still, lawyers!
So, the PU in the Golite coating with the flame retardant sounds like a pretty good deal to me. The PU might also cut down on the sag. Don't doubt the retardant might be hazardous in the factory, but not sure Golite tents are toxic in the field. Toxic tents! Nice alliteration, but it might be almost libelous, to make an allegation like that.
IMO, the OP made the right choice. And I'm working on a partly Epic tent, no less.
I do think it is worthless for bivies or clothing. The manufacturers generally use much higher HH material for clothing than for tents. We have to give them credit for knowing something.