Thanks for the response.
Wemo website does not list SmartThings; only Homekit, Alexa, Google and IFTTT. SmartThings DOES mention Wemo, but only in regards to 3 obsolete products. Why I was hoping someone here has firsthand experience.
Yes, IFTTT talks to Wemo. Unfortunately, Wemo does not talk to itself very well. There is something weird about the way Wemo communicates with its devices. For some reason Wemo often looses track of its devices. Amazon Alexa has the same problem, because it goes through the same Wemo cloud. Apple Homekit communicates directly with the individual devices via the local network, so as long as the device is connected to the network, Homekit can control it. IFTTT has the same problem as Amazon & Wemo, communicating with the devices via the Wemo cloud. I am hoping SmartThings will be more like Homekit, due to using a local SmartThings hub. Again, looking for some first hand corroboration.