I'm still unsure, but couldn't stand the virtual event trickery so tried a
different sin (adding undo_block_start/stop methods to the Text instance in
EditorWindow.py).  Like it or not, it's efficient and works <wink>.  Better
idea?

Give the attached a whirl.  Even if you hate the implementation, I think
you'll like the results.  Think I caught all the "block edit" cmds,
including Format Paragraph, plus subtler ones involving smart indents and
backspacing.