Please consider updating the firmware to add a way to change the hostname of a device. All of my smart switches share the same host name (HS200), which limits my ability to address them (in a home automation script) by name. (You might want to consider adding suffixes to each switch to make this sort of name collision less likely—so, e.g., a switch might have the hostname HS200-90ab, while another might be HS200-cdef, where the suffix is the last two octets of the switch's MAC address.)

I don't even need you to expose the mechanism in the Kasa app (though that would be nice)—it would be enough if there simply was a set_hostname command in the system command module.