lutron-caseta-pro VS lutron-leap-js

I imagine that you could look at the Python code in this Github and see if you can figure out the proper way to address it.

Yes, you can do this with the Caseta Pro hub and the Caseta Pro component for HA (https://github.com/upsert/lutron-caseta-pro)

Once you have it installed and configured, you'll need to install the Lutron Caseta Pro custom component. The readme on Github has instructions on how to install and configure. You'll also be need to pull in your Kasa plugs.

I haven't tested my own library with a QSX because I don't have one (and can't justify the cost), but some users have experimented with it. The python library has a lot more traffic (since it underpins HomeAssistant and not HomeKit/Homebridge) and very likely has been tested with the QSX.

LEAP is the name of the proprietary protocol that Lutron uses to communicate with its devices (via IP, not RF) like the SmartBridge 2, RA3 processor, etc. I've written a partial implementation to support my plugin.

The RadioRA3 integration is fairly beta: https://github.com/thenewwazoo/lutron-leap-js but otherwise RA3 is the best fit for you.

Here is a Github repo with support for local control of some RA3 LEAP devices. I've been watching that to track progress as (hopefully) more RA3 devices are added.

For those that don't want to jump through all the hoops, the real stuff is over at https://github.com/thenewwazoo/lutron-leap-js