I love this idea, but the typewriter mode in Scrivener isn’t perfect. It forces the cursor to be exactly in one spot. And when you start typing it can pop your line away from you.
A much better system can be found in Vim. It’s called “scrolloff”. It doesn’t force your cursor to be at a certain position. It just prevents it from getting too close to the top or bottom. And you can set how far that is. You have some free wiggle room in the middle of the screen.
So if you set “scrolloff = 10” and you are 20 lines from the bottom, nothing will happen. But as soon as you get 10 lines from the bottom, then it begins working. And if you do like it directly in the middle, you can set “scrolloff = 999”.
If Obsidian’s Vim mode ever gets the ability to use a .vimrc file, I’d love to set “scrolloff=20”, personally.