If this is about lung preservation then dry herb vapes are not really the answer. You end up inhaling deeper and get a lot
of vapor deeper into your lung tissue. Also ABV (already been vaped) bud still has a lot of potency, proving that you
don't get a full release of the entourage effects and nuances like flavors and smells you are looking for in different strains.
Now you have a pile of half-smoked bud and feel like you need to do something with it.
making edibles and tincture will "work" but you already spent 90% of the THC and left all the other sub-cannabinoids behind that
didn't hit a high enough temperature to vaporize.
I use to smoke a lot of bowls but that is the high temperature smoke that you can do. Ice bongs tend to make a person inhale too deeply
and does nothing to help.
I only smoke cones and I take in about half a hit and when I pull in the smoke, I pull in at least 50% air.
Basically taking large "sips" of smoke instead of burning like a fiend back in the old days.
As simple as this sounds, IMO, your best bet is to find a cooling solution that is easy for you to use.
A steamroller that is for cones packed with ice, an ice filled glass pipe, etc.
As far as the best dry herb vape I would go with a name brand, no knockoffs and the one I would get myself is a KHAN.
https://vapingdaily.com/vaporizers/khan-vaporizer-review/ 
No more big clunky rectangles that don't fit in your pocket these days.
