Salutations CheeseSandwich,
...where the wires connect to the bowl...
It's a closed fresh-air to cannabic path, starting from the inlet teflon connector (located behind) to the main white teflon mouthpiece (the one with a 14 mm compatible round end at the top). So, as a result there's no possible contaminant exposure (from burned wire insulation and such) at bowl level! The 50 Watts HA heating-element seems pretty much standard, reminescent of the soldering-iron era though you get 2 metal barriers insulating your inhalation path from all internals. An aluminium heat exchanger with concentric axial structures surrounds the metal jacket of that "ceramic" heating-element; teflon is present at the top aperture, at the heat-exhanger's base and also under the form of a short bridge mechanically compatible with the HA 3/16" (inside diameter) aquarium tubing system. A pump being optional in this particular configuration that makes the so-called bridge effectively acting as the fresh-air inlet i just refered to, previously. With the heating element correctly positioned within the HA heat-exchanger structure, considering there's a series-connected thermal protector feeding it, i'd say almost every reasonable effort has been made to account for teflon's operating parameters, including temperature. If teflon is OKay at 400 °C then aluminium should cause no serious concerns neither i suppose, which means teflon & aluminium use is probably safer here than in many other products not featured with safety mechanisms...
Anyway, overall the only substances making contact with my fresh-air/cannabic vapour path happened to be aluminium, screening metal (stain-less steel), teflon and PVC. Glass came as a 3rd-party option on the late.
The issues i have encountered with my HA v2.1 had to do with the need to moisturize cannabic vapour and also the time-scale involved, which made me prefer the quick, self-moisturizing, "1 Hitter" mode supported by a modded pipe.
Going digital won't render the HA sexier to me, expecially if the temperature knob is gone. More power in the heating-element, more contact surface in the heat-exchanger around it... That would be a start, ceramic as an interface between metal and teflon would be another.