Ugh, sorry for another long post but lots of topics being covered in this thread, as well as I think a breakthrough in isolating my odd noises. Sorry nothing solving EV range issues here, so feel free to skip this if that is all you are interested in, my post is all about climate control.
My experience with climate control on my previous car (Prius) as well as rentals is that climate control systems don't allow you to directly control whether warm coolant flows into the cabin, or the amount of coolant flow, like you can on a manually controlled car. Even in manual mode a climate control system only allows you to turn the AC compressor on or off and control the fan speed and which vents are used, but not coolant flow. At least in the cars that I have been in. In climate control systems you only have indirect control of coolant flow by setting to a particular temperature. The system then decides based on the set temperature if it needs to run AC or bring in warm coolant to maintain that temperature. Or use outside air if the outdoor air temperature is in the right "direction". Or if the set temperature is close to the current cabin temperature, and the outdoor temperature is in the right direction, then simply do nothing and allow the cabin temperature to change on its own, even though that might take a little longer.
I assume that smarter systems, especially hybrids where the engine is not always running, if the outdoor air is in the right direction (i.e. warmer than cabin air) they will be much more likely to use outdoor air when warmer air is needed, or else the "do nothing" method if the set point is close to cabin temperature.
Okay so now we have Clarity where the only way to bring in warm coolant if the engine isn't running is to use the resistance heater. One theory that has been floated is that it is doing this to maintain humidity. I think this is unlikely, or at least it would be mighty dumb to do this all the time and not just when the driver pushes the windshield defrost button.
The other theory (the one I was considering) is that Clarity is not being as smart as it could be when alternating back and forth between AC and warming to maintain the set temperature. Maybe while it attempts to maintain the set temperature it is sometimes using the resistance heater when it could be using outside air, or when it could also simply "chill" (pardon the pun) and allow the cabin temperature to warm back up on its own naturally from outside heating. But hey we have seen dumber things so the theory of there being a bug in the software causing the resistance heater to run when it doesn't need to is not that way out there, even if it is unlikely.
I actually wondered if the odd noises that I hear from the passenger footwell could be due to this, which is why I also was interested if it was possible to easily (and safely) disable the resistance heater at least temporarily for testing. But once I saw on the chart that it does not have its own fuse then that obviously isn't an option. As for unplugging the heater, that might throw a code, and anyway I'm with craze1cars I don't recommend experimenting with anything on the HV side of things.
And I have late breaking development in my noise investigation, I removed the plastic panel that is underneath and behind the glove box, the panel pops out pretty easily. I can now see the two different rotating parts that are making the noises that I am hearing. I can turn the temperature dial and at will make these parts rotate and make their odd little noises. I am not quite there yet identifying them yet or even taking photos but my initial guess is that one of them rotates to change which set of coils the air is flowing over, or if not that some other change in airflow direction. This one, which is a relatively large blue plastic wheel or disk of some type, I can cause to rotate back and forth at will by turning the temperature back and forth once I find the set point where it occurs.
The one that makes the odd tick/scratch sound that I hear is a smaller, white plastic rotating wheel/disk located closer to the firewall, which I am guessing controls airflow from outside in order to bring warm air in rather than having to run the resistance heater. If I move the temp setting a few notches, this "wheel" ticks and then rotates a few degrees (the scratching sound is the motor) then stops rotating, then about a second later it ticks and rotates again a few degrees, and it keeps doing this several times, starting and stopping (and a tickin' and a scratchin') until it reaches where it wants to be. If I then turn the temperature knob a few notches in the other direction, the wheel starts its approximately once per second movement in the other direction. I am guessing that it does it in increments so that it can measure the temperature change after each short movement and then increment more degrees as needed until it reaches the temperature it wants. Total guess on my part but it looks perfectly normal what it is doing, but maybe mine is noisier than others if I am the only one who hears it. If there was a cacophony of other odd noises I probably would not have isolated this one, but other than the brake pedal solenoid tick I really don't hear any other odd noises during driving which is why this one stood out, and also because I didn't start hearing it until a couple of weeks into ownership, which I now realize was right around the time that the weather started getting warmer.
but in our cooler months when mornings are in, for example say, the lower 60's, moving the interior temp from 70f up to 72f can activate the Energi's heater loop. When I see this, I adjust the climate control down a degree or two and the spike goes back to normal levels. Just turning the HVAC on or off typically causing the FORD GOM to jump anywhere from 2-5 miles depending on time of year. This doesn't sound like much till one considers this is on a 19 mile (5.5kwh) battery so that's a fairly significant percentage. 
