> Multiple installed emacs packages do not execute their code simultaneously unless they are using something like run-with-timer to schedule tasks on the event

> Multiple installed emacs packages do not execute their code simultaneously unless they are using something like run-with-timer to schedule tasks on the event loop. Yes, that's accurate, but that's the whole problem. The code executes sequentially, so each custom execution adds latency. It's not unusual to have elisp from several packages executing with every keypress.