I really liked milewide back and I was so disappointed when it stopped working. But actually I'm using the scrollwheel even more than the middle/left/right click. It would be really great if you could try to make it optional :)
While I appreciate you reviving the MileWideBack franchise, I do not share the opinion that the extension is better off without the mouse wheel spin feature (which, by the way, could be disabled in the original if it was a problem).
Two things about your version which I do like: unlike the original, it does not embed a white vertical line on the left of full-screen videos; and the Extrawide feature speeds-up the alignment of non-full-screen browser windows with the edge of the display.
I've been using the original MileWideBack for many years and always experience unwanted 'spin'. I love your modification and hope you continue to update it.
There is one minor issue. The first two or three pixels on the left edge of the browser window are always black. It would be great if this vertical bar could be removed, making the entire browser window visible. If not, is there a way to reduce it to one pixel wide? If not, no worries, your extension is still a must-have.
I'm on Developer Edition and have been missing MWB since ver. 44. You're just a life saver. I, like anyone else here, can live w/o "spin." (Ctrl+Tab will do the trick.) All the rest works just fine for me on FF 45.