Thanks. Sounds like that should work, but:
I disable the Alexa skills for both Wemo and Kasa applications, but same results.
Then I wait about 24 hours, reboot, restart everything, same results.
Then I uninstall and delete both nodeservers from Polisy, delete all Wemo and Kasa devices from ISY, reboot and restart everything, same results.
I ask Alexa to discover devices; she finds one Wemo device, but I still can't add a spoken for that device.
I still must be missing a step, or there is some other issue. So, I'll open a ticket.