Because of your posts about Firefox, I downloaded and tried it - and it works! Thanks!
So it doesn't work on Safari or Chrome on a Mac (The "double A" symbol is just not there at all on these browsers, it is just empty space on that upper right of the editing/posting area), but it will work on Firefox. And now my monthly editing sessions will be much easier.
The only thing, similar to what DaleDe says, is that spoilers are still coded and show up whole in editing. It would be so helpful if spoilers would close up too because those are what really make it so hard to edit my lists multiple times. But just the bold alone makes it easier to find things I need while editing.