I know I didn’t put adaptive in there, but that is what I meant when I said the triggers don’t work.

Yes, I understood, but I wanted to clarify for the sake of other readers who wouldn't. Most people who don't have a DualSense don't know about its adaptive triggers, since they're not a common feature on game controllers and not used by most games.

And how do you get the touchpad to work? I can get the buttons on it to work, but I haven’t gotten the mouse-like touch input to actually work, despite being able to map it.

On the desktop, I didn't have to do a thing. It was automatically recognized when I connected the device, and I could move the mouse pointer and click right away. (I ended up disabling it in Xfce, because it sometimes got in my way.)

In Steam, I usually remap areas of it to produce keyboard events (useful in Elite Dangerous), but I think it can also be mapped as a mouse. I haven't fiddled with Steam Input's many options in a while.