The MFLB stems make great GH attachments, they fit in snug and do what some desire. (direct draw is nicest with bare Ti IMO)
Best advice though: portable charging sans tether
This Rapoo P500 10400mAh powerbank matches well with a dual
Universal Li-ion cylinder charger.
It uses about 6-8% of its capacity per battery charged.
I can usually only get 2 chambers out of one battery, if I'm trying to get dark brown AVB.
However, if power is limited, I can get more clouds into me at the price of less thorough extraction.
There's the majority of AVB I've put through my hopper. On top is an intact nug for reference.
The slight green that is showing in amongst the rest, is brown and crispy in person, but this shows the varying levels of extraction the GH can offer. A key take-away point would be how consistent each piece is in colour with itself.
I've had the pleasure of using the Mighty since owning a GH, and if a direct draw device is what's desired, then this more premium device is the better option. The flavour is ongoing with the Mighy, where as the hopper definitely degrades this experience at higher temps.
For vapour bongs though, the hopper rules. Noticeably thicker vapour and faster onset. A couple of times with packed out chambers I've been almost certain the hopper has started combusting, only to check, once after a couple of bongs later, to find even, golden AVB.
It's pretty amazing.