Might as well type out an update here, for posterity.
I bought the Autel HD (J1939/J1708) scan tool a while back. Figured I couldn't go wrong since it also does all the other automotive protocols. Good value tool for $109.
It readily connected to the ECU, but still couldn't do to the official "scan codes" or "clear codes". Unsupported functions. But, at least this scanner doesn't kill the engine when you try these functions. And again in the "freeze frame" data, I could see the code for the Air Control Valve.
So finally, I threw in the towel on my own diagnostics, and loaded her up on the trailer.
My closest Kioti dealer is only ~10 miles away. They gladly received my machine, transferred the warranty for me (since I didn't buy it there), and got it into the shop within a week. As suspected, the air control valve was at issue. Supposedly it passed the diagnostic tests they can run, but still kept tripping the CEL code/light. So they ordered a new one for me, it arrived within a week, they promptly put it in, and voila! No more codes, running great. Free repair under warranty - bad ass.
I wanted to build some good will with my dealer and sort of say thank you, so I bought an implement they had sitting in their yard that I had been keeping an eye on - Bad Boy 72" land grader.
I tried it on my frozen, bone-dry gravel driveway upon arriving home. Kind of dissapointed, but the drive was nearly concrete. I knew I'd have to wait for a thaw and some moisture.
A few days later, and Muuuch better:
Also found time over the holidays to get my hydraulic top link installed. Easy peasy!
Had to clock the cylinder hose port housing to the side to better clear the fuel tank at full lift. Almost made a very expensive mistake first...
Just to be safe, I found a snug fitting spare bolt to slide into my 3-pt control lever slot, to just slightly limit the full lift height (still plenty).