[DiapDealer]

I doubt we'll be seeing much change to how the Open With Feature works. Book Browser may look like a regular Tree View of the file system, but it's highly specialized to work with Sigil/Epub. It's not going to mirror the underlying OS context menu. We're not likely to add potentially 5 different shortcuts for external editors directly to the main level of an already quite busy context menu.

Plus the External Html Editor toolbar button is completely separate from the Open With feature. There will be no interaction between the two features. The Toolbar button was mainly added for use with PageEdit--which allows all xhtml files in the epub to be viewed and edited.

The Open With feature is the one for customizing multiple external editors to work with different filetypes.