Phatass & oblivion, smoking benzos can be done however toxic it is. I've smoked pure diazepam powder via tin foil and it gave off a very bad odor along with blue colored smoke (cannot be good) - when you put a flame under the tin foil it turns blue, highly regret doing it esp since I had a 4mg/day clonazepam tolerance. I also smoked phenazepam via tin foil and meth pipe strictly b/c the effects were instant compared with its 3-4hrs oral onset, it worked better in a meth pipe however that is not that point. The point is when I chased phenazepam instead of turning blue it turned purple, which I know for a fact is a (def) sign of pyrolisis which results in very toxic carcinogenics (MDPV also undergoes pyrolisis when smoked via smoking).
In conclusion from past experience I can say that if you have the pure powder smoking will be very toxic. I personally have *regular* chest infections every few months like a Swiss clock, unexplainable symptoms - not withdrawls but rather sweating in both +30C or in -30C weather. Many conditions I know for a fact came from smoking things beside weed & hash. I was a (successful) heroin addict for almost a year, using up to a g/day of east coast nr.4 by chasing the dragon...anyways one of the dealers around here got busted and his dope taken to be analyzed, it came out to be 48% or 49% h. The dope wasn't the best, there is dope that can be upwards to 50-60%, this was average quality that we get around here in our little town. Point being the smoke I've inhaled over the years from diverse chemicals have caused me lung problems (only 27yrs), recently I was diagnosed with a lung infection & give antibiotics to take for 10 days but I get these infections regularly, that's my concern. I also take 2 puffers a day, the red one the most and the blue one when needed & I know plenty of heavy weed/hash smokers that don't have the lung problems I do. Lastly I am very sensitive to colds or any lung/chest related issues.
p.s. Never tried flubromazepam but hope its good. I will try it eventually, sooner rather than later and let you know my thoughts on it.