All that parsing and rendering can be done in the background, not grinding the UI to a halt. As soon as I strike a key on my keyboard, the letter should appear.

All that parsing and rendering can be done in the background, not grinding the UI to a halt. As soon as I strike a key on my keyboard, the letter should appear. Instantly. (Ok, in 20ms or 40ms or whatever) If I'm actively editing a markdown file, I do not need for it to fire off a re-render on each keystroke. It can wait 500ms before starting to do it, and cancel if I hit another key in the meantime. If I start typing after it has started rendering, then go ahead and finish that cycle while still showing me what I type in real time. However these events are scheduled, the appearance of my typed characters on the screen is going to always be the priority. There's no reason to block UI while doing this.