I have ZERO worries butane. If you are using a clean burning torch lighter, you should have no worries about "butane in the air path".
Butane burns clean if you buy good shit. Don't buy junk.
Lily/daisy have a clean air path.
Candle flame lighters do work, but deposit soot on the filter and takes longer to heat up. Torch flames are superior imo. The coil and bats were harsh for me to use dry.
I wouldn't rule out the ascent at all. Air is what my buddy calls the "K.i.s.s." Vape because it's so simple.
Ascent is I little more quirky but the Tass is superior to an air Imo.
I really want to try a haze!
Vapman is a beast! Don't let the small size fool you! Milks glass like a boss..
Coil is best used with water.. Harsh and sketchy aiming s torch towards my face. Full size VGs are great though. No worries about butane with a clean burning flame
I never attached until heated but I dunno how others did it.. Only difference is conduction is quicker. I would watch some of @paytonpenn s videos on the hammer, he's got some super fast session video as well..