Hi Nexians.
I've been doing more experiments and have come up with something that, for me at least works brilliantly. It was super cheap as well.
Basically it's a dream maker on a stand. The beauty is it's super easy to use alone. Just suck gently on the top tube and waft the flame about 2 inches below the spice, and off she goes.
I added a hole in the side of the jar to help clear at after the toke but to be honest that doesn't work so great.
The metal disc with the hole in it is to stop the foil rising when you suck and it works perfectly.
Enjoy our weekend

Fancy device! Looks quite hefty but also somewhat portable. What's source of heat?

Did you install a temperature gauge? Make sure to reduce any waste of the material and keep the flame steady around melting point.

I just use one of these Jet lighters.
It's really easy. Just suck gently and move the flame up. Once the vapour starts to rise then back it off a bit. When the lungs are about half full remove the heat and empty the jar.
If you try and vape the spice before sucking it doesn't work very good at all.
And yes it is quite large, but very portable. It's doesn't weigh anything.