Sorry to dredge this up, but I just realized I totally forgot to report back on this after all the pandemic stuff that was going on at the time. Figured I'd leave my solution in case it helps anyone later.
So everyone that said to do the PCV was totally spot-on. I first tried cleaning the throttle body & MAF sensors - but they were both quite clean before I even started - and that had no effect. Then I swapped the $45 rubber PCV diaphragm & spring (old one was almost black and the rubber was more than 50% torn in a circle around the outer edge). Once the new piece was in, the CEL and idling issues instantly resolved.