If you have a large note, say 30K+ words, you may find that there is a delay between when you type into the editor and when the characters show up.
We have found that this delay is often due to the built-in spell checker in your web browser. You can try disabling your spell checker temporarily to see if that speeds up the performance of Notejoy.
We've also found Notejoy's desktop apps don't exhibit the same lag because they use their own spell checker, as opposed to the built-in system spell checker.