@ClifM
I'm sure you realize switch #1 is simply switching the line circuit, and that the return neutral comes back to the same wall-box. Obviously you can use any smart switch I've seen in such an installation.
Of course #2 is different, it passes only the line current to the switch. Stupid, but my goodness the stuff I've seen electricians do to save a few pennies.
On a completely unrelated note, did you know that while the purpose of a ground wire and a neutral are different, they are electrically identical?
On another unrelated note, did you know the Kasa only uses neutral to run it's own internal electronics? Not much current flowing there either.