Do any of these tips help the issue where Gutenberg grinds to a halt if your post is longer than a postcard?

That any editor should need a "Top Toolbar" mode is ridiculous. This and Fullscreen Mode seem to have been crammed in last minute to pacify critics. The WordPress Philosophy guidelines clearly state that WordPress development should be guided by "decisions, not options."

But then again, the guidelines also state "the average WordPress user simply wants to be able to write without problems or interruption," and "we want to make WordPress easier to use with every single release." A lot of WordPress Philosophy has evidently been thrown out the window with Gutenberg.

Gutenberg is a disaster. It makes WordPress less accessible, user-friendly, and goes against WordPress's own philosophy of simplicity and designing for the majority. It should be removed from core.