An addon everyone really needs.
This said, with this new WebExtensions version, the UI of this addons is REALLY confusing. I certainly do not like the two/three step method at all. I rather prefer the 'old' interface of the classic Add-on version instead of this strange and non-intuitive WebExtension version.
Uninstalled, and went back to the classic version.... :(

(going to disable updates on FF56 anyways)


EDIT, after reply from creator:

- I really do not see the need for a (forced) prep-stage... If I want something to prep before printing/editing I would have done that already on the page itself, before activating the print edit, because that is what I would like to print edit. It is a useless step and unfortunatly can't be 'disabled'.

- Duplicating the tab: I could live with that, but I rather want to go directly into the dedicated print preview window from the File menu, like before. Makes much more sense and has less steps to go thru.

- Also, I could Print Edit any previously saved page before with the classic version. So, no benefits there either.

- The only benefit I see with this new approach is that you're able to edit multiple pages at the same time. But that is something I never have the need for and thus never do.

Conclussion: compared to the classic addon, it has far more downsides than improvements for me. Still I appreciate the effort and skills though!
If you would re-introduce the File>Print Edit again, to go directly to the dedicated print preview window, I might reconsider.