If you want a summary on the history and state of parinfer, daniel did a great job distilling our conversation about it in this podcast: https://www.therepl.net/episodes/17/

That Atom (and therefore smart mode) might fade into oblivion at the hands of Microsoft makes me apprehensive. I really, really don't want to go back to paredit and its 1200 keyboard shortcuts.

There is some hope we will be able to add smartmode to Calva. @mseddon has created this thing he calls DocMirror that I think might be able to track the changes for us.