Is there a way to edit the layouts of the FAM reports? The Customize Report Template page give you a very little options... I want to edit the layout like the Advanced HTML/PDF templates.

I doubt you can, you add/remove columns, paper size and orientation only through customize report option. Since FAM is a scripted add-on (originally by Nolan) it is not customizable.

I found a way in the docs.. https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/section_4688267909.html#To-add-or-remove-a-field-from-the-default-report-template%3A this would work if you could override the XML file in the File Cabinet, but you can't, all the files are locked.

That's what I meant - locked source files

Got it. It is weird that the docs suggests this.