Concurrent editing problems

[virgile-dev]

Describe the bug
When many are editing the same document some problem can be noticed

• The “/” shortcut, which lets you set the paragraph type or add an element, doesn't work very well when there are “many” (wet-finger ed.) simultaneous edits: this menu then tends to appear and disappear almost instantaneously. The more general problem is perhaps the preservation of the positioning of one's focus when editing the same paragraph, as I've also had cases where when people add text below or under my paragraph, the paragraph that was active for me would move...
• same issue :emoji menu
• when you edit the last paragraph (the empty one at the very bottom), there are many jumps in the interface, making it almost impossible to define the type of paragraph / element, or to insert an element with the “+” in the left margin. Bypass: add another empty block below the one you wish to edit.
• It's hard to scroll when many edit at the same time, the page keeps scrolling up and down depending on where the edit happen

Misc

• Node version:
• Package manager:
• Browser:
• I'm a sponsor and would appreciate if you could look into this sooner than later 💖

[sampaccoud]

the format bar would also disappear before being able to click on an item. It's like some events popup and disturb the action we were trying to make...

I also noticed that some broken behaviors disappeared after reloading the page, tending to demonstrate that the excessive load had broken the editor. It's not just overloading, it's breaking it.