So, I’m not sure what you mean by
Every thread seemed to reference it working as a smart vent, and not just an on/off like mine appears to be doing.
The vent opens & closes. It can report pressure, temperature, position, & battery level (though I’ve never been sure it’s reporting the battery level accurately). If you’re in HA Devices, find your vent, open it & you’ll see the attributes except position. To see that click on the left side of the control & you’ll find position. That’s what a “smart” vent does. (I’m using it with the same dongle, but I’ve got it connected through Zigbee2MQRTT.) You have to control it with HA. You can easily create an automation to open or close it fully or partially depending on the temperature.
Hope that helps.