Yah breathing in smoke from a fire is generally ill advised. So is huffing gasoline. Or leaving a car running in a garage.
Generally I think the sealed container with a charcoal fire compartment underneath is a better way of doing it than a partial combustion one, simply because it is much easier to seal it up properly, and you end up getting a better mix of combustibles.
The regulation for the average content of benzene in US gasoline is .62% and the WHO, as of march, classifies gasoline in its totality as a IARC group 1 Carcinogen.
Group 1 does not denote risk, just that it is definitely carcinogenic.
Again I’m not diminishing the fact some products of pyrolysis produced in significant amounts are very hazardous and carcinogenic, but I think you underestimate gasoline.