Your comments

I'm the inventor of elastic tabstops, and that is not a working implementation of my invention. If the API for a text widget does not allow the user to move tabstops to non uniform positions on different lines then it is impossible to do a proper implementation. The package you linked to modifies the contents of the buffer (by inserting spaces) rather than working on the view (by moving tabstops since Sublime Text lacks that feature), and so completely misses the point of my invention.