Wow. I've had this personal clevo laptop for four years, it's great, the only disappointment is that it doesn't have a display signal over its USB-C connector, meaning I need a separate mini-Displayport cable to my monitor, where all other work laptops can just use the USB-C cable. It not supporting a video signal over USB-C is confirmed both in practice by my monitor, as well as by rereading the specs on the website which I didn't do properly before buying it.

Turns out, four years later, that I just need to turn on this feature in the BIOS? It could do this all along?

The setting is called "DDI to Thunderbolt" which was set to "DDI to mDP". This disables the mini-Displayport (you can't have it both ways) but sends the 'digital display interface' over the Thunderbolt/USB-C connector. This should also allow me to use my MHL cable to watch Netflix on my mother's tv (USB-C to HDMI), which previously involved a more complicated screen mirroring setup with my tablet.