Quick post about the aluminum alloy electrical conductivity issue. In virtually every case, alloying elements reduce the electrical conductivity of aluminum (pure aluminum being a curious anomaly, but it's so soft as to be irrelevant). Here's a quick link to conductivities of a wide range of aluminum alloys:
https://www.nde-ed.org/GeneralResources/MaterialProperties/ET/Conductivity_Al.pdf
Regarding heat treatment: If you peruse the table, you'll see that a T0 temper almost always yields the highest conductivity for a given alloy (where T0 is an option, which it is for the high strength structural alloys being discussed, although values aren't given for all alloys in the first link). Unfortunately, T0 is a full anneal - the softest condition. Which pretty much negates the use of a sexy high strength alloy in the first place.
Alloy designations
The 2000, 6000 and 7000 series aluminum alloys in particular are designed for uses demanding their excellent strength to weight ratio when used in a proper precipitation strengthened condition such as T6 (low conductivity, remember?). They are seldom used as electrical conductors. In many cases (vaping mods being one of these), the resistance of aluminum is dictated more by the contact resistance between the alloy and another element of the circuit (such as your battery) than by the intrinsic conductivity of the Al alloy. Silver or tin plating can be used to protect the aluminum and reduce the contact resistance, but it's difficult to implement in a vaping mod. Keeping your aluminum contacts clean and (nearly) oxide free should be your primary concern.
Here's a good read comparing the use of aluminum and copper in electrical equipment.
http://apps.geindustrial.com/publibrary/checkout/Alum-Copper?TNR=White Papers|Alum-Copper|generic
YMMV
