But this plugin is, framed in terms you might be more familiar with, a plugin that wraps the "shell out to the tmux pane then copy the output into the buffer I'

But this plugin is, framed in terms you might be more familiar with, a plugin that wraps the "shell out to the tmux pane then copy the output into the buffer I'm in" step. That's it. This isn't a vim-integrated shell solution, it's a way to avoid those, for exactly the reasons you say. Repl integration isn't about embedding a prompt in your editor, it's about bypassing the interactive prompt because you already have a place to write and read text - an editor buffer. I should have used a different term obviously, that one is actually misleading. Part of the reason I'm curious is I regularly do Clojure training and see this pattern over and over: "I don't like working that way, that sounds bad. [hours later it clicks] Oh! I see what you mean, this is great. This is the way I like working but easier! I thought you meant something different".