Sprinklers in portable domes...
We used to have deal with this at Elumens all the time. Rick Zobel handled all of our fire marshal placation issues, and here's what has to say about it:
Phew! This is not a new request....
There used to be "portable sprinklers" available (at a substantial cost and integration time), however we never found them to be practical. Orlando was, as I recall, the worst with this. To satisfy them we had to provide certificates of retardancy for all the fabrics, plus send plans with locations of the extinguishers, plus mark all egress methods, plus have dual linked detectors, plus have glow tape marking paths on the floors, plus prove that the screen would not collapse too quickly.....
Another request was linked smoke detectors interior and exterior that the fire marshalls would test daily that they also wanted linked into the full convention center system, but it never came to pass.
Finally, a last option was to pay a fire marshall representative 24x7 during the conference to monitor the booth. We did have to do this a few times as a last resort as I recall.
Basically they are paranoid about enclosed spaces with limited egress and potentially flamible materials (go figure...). In every case we were able to come to some comprimise that suited everyone (or lined their pockets enough to satisfy them). Start with the Convention Center and then work your way up to the Fire Marshall.