Im sad to say that this addon should be fantastic, and it is ESSENTIAL given FF pathetic print function, but the UI and information is so clunky and badly designed that it's vitually unusable. Periodically I go back, spend half a day trying to print ONE page, and give up. Other devs have an issues page on gitlab or wherever linked from the add-on page, and end up quickly with user friendly, bug-free apps. I would strongly suggest this, DW-dev. The issues are too many to go into in a review page and I'm not interested in spending more hours repeating what no doubt hundreds of other frustrated users have emailed to you, (although I have screenshotted them all and WOULD be happy to put in an issues page, if they are not already there. You would save yourself a lot of time reading emails, as well).
Just a couple of examples of primary school level issues:
1. your tool bar and dialogs should size to window, not to zoom so you cant see them if your window is not maximised or you are zoomed out viewing a large selection.
2. Available formatting should be in a sidebar with existing formatting and adjustment tools displayed side by side, not covering the selection you are trying to format, and have to close dialog to see either of the other 2.
3. Lables like "float", "clear", "block layout" need context menu instructions and explanations of what the options are supposed to do.
4. After spending hours trying and comparing each setting, you've got it right, then preview-its a total disaster and no idea how to fix it. Top element just isnt here. Next element repeats on 3 pages, page 1 and 3 otherwise blank. Zoom to fit - doesn't fit. Header and footer outside printer area, bleeding off the edges (no adjustment option). How about edit in a PREVIEW view.
5. Oh, and cursor selection is complete malfunction. Selects an area totally unrelated to where you have dragged your cursor. (Same issue noted in Web Paint.)
Back to Fireshot and greenshot.