Ship the one-pager
If you cannot explain the idea on one page, you do not have a magnet yet. You have an outline. The generator can wait until the outline is a page.
Make it ugly-useful
Boxes to write in. Numbered steps. A place for their URL or offer. Interactivity is why people keep a PDF.
Then decide if it needs a cover
Covers help on a sales page. They do not help in an email attachment. Generate the interior first.