AFAIK, with Configurator 3.x, none of the "AdobeInvoke..." functions would return a value, so all communication was one direction, from the HTML widget to the application scripting environment. It's feasible that you could write to a file from a script that the HTML widget would be able to access using AJAX, but I never got to trying it.
I was hoping that the new "_Adobe.JSXInterface" methods would provide a way to get return values (and they probably do), but with the version of Configurator 4 that's currently available, the "_Adobe" object does not appear to be exposed in the HTML widget's scripting environment. I tried completely rebuilding a panel with the new configurator and running it in Photoshop CC, and it gives the message "Can't find variable: _Adobe".