gHE - golem Hot End
All metal with PTFE tube for "lubrication". since it is enclosed all the way from hot to cold in single piece of machined tube it has no room for deformation. Or you can change the barrier and go without it.
You can omit the secondary block and make simple version or go full and put 2heaters and a temp. fuse (it may be just placed loosely, droping down into the heat exchanger, those are designed to work even with air temperature and don't suck heat away, hence no need for heater like mount.
blue - stainless steel grey - aluminium kinda orange - brass
An if you have a clog or wish to change diameter or fast for precise nozzle just do this in 40s: youtu.be/UO7ny72T9k0
to entertain guests consider doing this : youtu.be/MJHYccneEeM
And as long as you keep to the oh so complicated heater and cart mount interface you're free to experiment with nozzle designs
If you have any questions feel free to ask via email or forum:
here installed on golemD - GolemD
(foto by kanap) here installed via simple aluminium plate, hand cut and drilled, to an ABS reprap style Xcart