Ok, it should be working now.
As I said, I was out of town for a while, and this was a major change to how Tesla had been embedding the option codes. Now instead of just getting all the option codes from the inventory lists, I have to query each car detail page to extract all the option codes.
Are you using something other than AP04 for Hardware ~3.0 vs 4.0? This MX Plaid has the AP04 code (and was built 4 days ago), but listed as Ap Hardware ~3.0, so curious if you're using something different?