RE: 10,000 Free Flight Fire Balloons
Chinese Lanterns are now common-place in England.
Same technology, but only about a 1/4 of the volume.
As long as the fire is burning, the balloon is NOT coming down, so the fire risk is tiny. When you watch them, you see the fires expire whilst the balloons are very high.
They are remarkably compelling to watch.
I've little doubt that, somewhere, some authoritarian-type, will declare them to be a risk that is not to be tolerated.