wolfssh VS hs100

I haven't written a KDE Connect client, so I can't say much on whether your approach makes sense, but I'd ask whether KDE Connect is the best tool for the job if what you want is to execute commands on your PC remotely - you could consider something like WolfSSH that does not depend on having KDE Connect running.

I accomplished this with Homeassistant on a raspberrypi, and kasa tplink plugs and switches set to local server use with this code https://github.com/jkbenaim/hs100 I added this code to my phone using termux so I didn't have to lug a laptop around the place to initialize them. Once initialized to local server only you won't need the code again, unless you reflashed your plug firmware. Then in router blocked all tp mac address from reaching the internet (just as a failsafe)

This code lets you initialize kasa plugs and switches to only use local lan and not need kasa app. https://github.com/jkbenaim/hs100 to make activating them easier around the house i installed this into termux app on my phone because you temporarily have to wifi connect to them directly. Then I skip google and use self hosted homeassistant server