Changing text on "QInstaller.Introduction" page is not possible via script

Trying to add a simple widget label to the intro page. I understand I can add/modify the welcome message by changing the text in the IFW source, but I wanted to avoid having to rebuild every time and rather add a widget to a page, just like the registerfileextension example provided in the repository.

The behavior is the following:
1- intro page shows the regular message
2- click Next
3- once in the targetDirectory page, click back
4- The label now appears in the intro page

I'm including my script and package.xml for your reference.

One more question....
When my intention is to issue an statement like: "installer.addWizardPageItem(component, "RegisterFileCheckBoxesForm", QInstaller.Introduction);", which is component independent, on what file should this be included? I ended up choosing an arbitrary component folder, but I'm thinking there is a better insertion point.

Thanks for your help