I’m another that relies extensively upon system-level automation, it’s a bargain for what you get. Instead of being dependent upon individual software, everything just has it and in a uniform sense, from open source software on down to Adobe. And since it is system level you can glue any number of programs together. When I’m done typing here, I’ll hit ⌘F3, which converts what I’ve typed in Scrivener into BBCode, puts it on the clipboard, switches to the browser, selects the right field, pastes and finally, clicks the Preview button then switches me back to Scrivener. Considering how many times I do that, it’s probably paid for itself just with that one macro.
But that aside…
As to whether this has been discussed, it has, but so many years ago you couldn’t be blamed for having missed it or its more recent follow-up thread (including an explanation for why scripting never went anywhere).
Another complication came up after that thread was first started: Windows. Ideally a modular or script-driven system wouldn’t require coders to write in two completely different scripting languages to support all Scrivener users. But no matter which language such a hypothetical system used, it remains hypothetical at this point in time.
If you don’t want to check out the third-party options, AppleScript can do a little with general interface manipulation. It’s similar to what you’d be doing with a macro tool, but of course freeform instead of using a library of actions.
What are you looking to do, along the lines of automation, by the way?