They do local echo on changes to avoid jumping back and forth while requests are ongoing, however some areas modify the checked state after the toggle has mounted.
Fixes https://github.com/vector-im/riot-web/issues/8432
Also bring in the compact timeline option.
Without minor CSS changes, the old user settings are completely unusable with this change. As such, minimal effort has been put in to have it be useful. Similarly, the changes drop the use of radio groups and the old theme selector was the only one that used it. See the comments for more details on how/why this was mitigated the way it was.
Michael Telatynski