Halotron is not the same as halon, halon was started to phase out of circulation more than 2 decades ago because of ozone depletion.
So you have two choices:
Halotron
or
3M novec - which is about 300 dollars a gallon.
Yeah I am phasing out miners with a draw north of 1000w, in my experience that is the threshold which leads to fire. I have had the lower wattage miners burn up, but never with a resulting flame. Shrink the mine down to 20TH and hold, expansion with current return and specs on gen 3 just does not make sense.