Also, note that since 1 Kasa switch works in the "far"/load box, it must take its power from whichever of the two travelers is currently energized (probably with some capacitance to float over the...

I think this gets complicated because there are two problem areas: electrical wiring and Kasa app state tracking (i.e. is the light (load) on or off?) The state tracking problem is because 3-way (and...