I agree with everything you wrote, but the way I see it, the mflb screen is one big heater that will heat the air that comes into contact with it, which is the whole trench.
The air has more time to stay into contact with the hash, allowing better extraction. Of course you will still have to break the hash up a few times as it will congeal, and not vape as efficiently as it would if it were to stay apart because now you're doing convection vaporizing instead of conduction.
True, it will heat the air all right, but most of the air it heats is then either sucked out of the bottom or rises uselessly to the lid to cool off. There's no action to force the air into contact with the hash, in fact just the opposite.
There's barely enough power in conduction (it almost demands the PA at full blast), more than you'd use normally for bud. Going from conduction to convection needs LOTS more power, we just don't have it available in MFLB.
There's just too little hot air (and most of that going the wrong way), and what there is is
not hot enough. Too few degrees. It can be done, the LL Cera cart does a great job with bubble. It just uses
a lot more energy to make hot air and directs that
hot air through the load......two things we don't have working for us here.
Good luck with your very rare 'BHO like cleardome'. You might be able to melt enough to get some in the pad? However, basically nobody else has access to that stuff. Folks should understand that the bubble hash at the local dispensary is not going to work. The only concentrates there that will work are the solvent refined oils and waxes that pass the foil test.
OF