I’ve not louched into Heptane, and I (now) recall that ethanol/heptane/water DO form a ternary azeotrope. see @photon_noir’s Ethanol Azeotropes - Attn: EtOH cannabis extractors!
I have watched @tweedledew’s process (into pentane). THC content would only exceed 0.3% if you actually centrifuged the ppt out. which is not the object of the game.