In my case, it's not a syntax problem but a transport problem. The JSCRIPT objects created within the context of the extension either are not 100% compatible with the JavaScript code or they lose some of the context.
I developed my framework code within the TestComplete IDE so I had all the syntax stuff worked out. It even worked PERFECTLY in that IDE environment because it was all JSCRIPT. So, whIle the SDK might have a lot more power, I think Script Extensions are still viable for framework construction.
EDIT: Specifically, the JScript array does not support the spread syntax. IF, somehow, I could create a Script Extension in JavaScript... THEN... things my be different.
