Sorry Michele but extgwt has not been tested with ME4S. The code generated by the scaffolding uses GWT, but not extgwt. That’s not to say it will not work but like any tool that can work within an IDE, you’d need to verify it yourself (unless another kind user has tried it and can post a response here).
Whenever you get the chance to test it, you may want to request an extension to your trial license. That way you’ll get another month to try it out.
To extend your trial, when you start MyEclipse for Spring, you should be prompted to enter a license and there should be an option to extend your trial. If that doesn’t happen for you, please contact sales and tell them your situation, I’m sure they’ll extend your trial in this situation.