And that’s a part of why I said the approach is bad: there’s a long tail of native features that depend on being able to see/interact with more than just the current word or selection or whatever, and you’re thwarting that. You cannot make a lot of them work, and the more effort you put into trying to cover them, the more you end up with something even unholier than contenteditable.

Give up. Seriously, please. Switch to DOM, it is genuinely mandatory for acceptable results.

You can get close enough on desktop that many users won’t notice, but you emphatically cannot reach even tolerable on mobile.