If a device is not in BOOTSEL mode but is exposing a reset interface along with STDIO USB, then we can potentially run any command by first resetting the device to BOOTSEL mode, and then performing the original intended command.
Open question; if we are performing an operation other than "load -x", what should we do after - the device will be left not running. We can either reset it or expose the USB interface at that point (in which case we may as well expose it as soon as reset if we won't be resetting again after the command)