It turns out I got unlucky. There was a chance that my recent pair of trouble codes were just the temperature control valve, which was replaced and works fine. But the inverter coolant pump was also actually bad. It went kaput here:
https://www.instagram.com/p/CgChQJ1rZaP/
So the next step is to replace the water pump. One is on order and I should get it soon.
I'm also thinking I should get serious about making sure the thermals are air tight before I do my front mods. I would hate to have to do a bunch of work... just to redo it all again if something else fails. On the bright side, everything seems repairable for the moment. While stuff needs replacing, nothing seems to have been irretrievably damaged. Yet.
