I'm very thankful I have smart friends who know to check the things I very obviously missed. The ESP32-C3 that I bought originally was the wrong one. It wouldn't be able to send the information I need over USB. It could do it through Bluetooth, but that's been extremely temperamental on this particular computer at the best of times. I'd rather use USB if possible. Quick search online confirmed it, and I've now ordered the correct boards. In for a penny, in for a pound.

If anyone has any fun ESP32 projects to recommend, I'm all ears. I'll have four ESP32-C3s, and 3 ESP32-S3s, assuming all goes well and I only need one for my HDMI-CEC doo-hickey.