FYI. One can set a USB-C port to output 5, 9, 12, 15, or 20 volts. I bought this adapter and plug set to do that, but it looks to be discontinued. There are other brands that do the same thing.
https://www.amazon.com/FARSENSE-Adapter-Trigger-Connecor-Pressing/dp/B0BGFC77M6

I set it to 20v to power any or all of these:
- laptop (19v input)
- asus router (19v input)
- portable tv (12-19v input)
- home alarm (16v ac input, accepts dc just fine - full wave rectifier input)

Your USB-C port should be capable of up to 100w output like my EB55.

This one is back-orderable: https://www.amazon.com/dp/B0BGFC77M6

Seems crazy to me that these aren't everywhere. Can't even find them on AliExpress. Everyone has a selectable-voltage USB-C power supply. Everyone has various devices with a barrel connector that take various voltages. You would think a USB-to-barrel cable/adapter with selectable voltage trigger would be a no-brainer. Carry one thing to power everything/anything.

I have a TC66c that I can use to trigger any voltage I want, but it has a USB-C connector on both ends and I thought another solution for me would be to just buy a "straight" USB-C to barrel cable, but that doesn't seem to exist either. All USB-C to barrel cables have built-in triggers in them with fixed voltage. Ugh. Can't find these things anywhere.

Could make my own cables, I guess... May have to resort to that.