Got some work done on the code editor in the algorave software I'm working on. Pending inserts/deletes have green/red bg (allows "local commits" in the doc). It has colored text, and also stretches text based on caret proximity.
Try it here: https://veralin.dk/dodemos.html
You can cancel pending inserts (green bg) by pressing [ctrl]+[space] on them. Here I do that "by accident", but then "undo" it by time travelling to the past ([ctrl]+[z] and drag), copying the text, and pasting it after returning to the present.
These features are meant to replace undo/redo (which gets a bit weird in multiplayer)
aks