I don't recall who discovered that one, but it's actually in the manual, albeit disguised with misleading language that calls it "automatic." Using the floor only setting, partial recirculate, and a fan speed of either one or two (if the windshield starts fogging) will give you the most efficient heating you can get without full recirculate, which tends to cause fogging.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.