A single server would be more efficient than multiple independent instances

Seems like a fun project :)

If you need to process multiple org files, and you're currently running a separate instance of Emacs for each one, you might consider starting an Emacs server (which can be specific to this use-case), and using that each time.

(I think you'd notice the difference if you're currently loading all the org libraries repeatedly, and you dropped that to "just once".)

I expect you've probably considered this already, though.