I use this code in my global.js

// Expand all grouped RC/Watchlist entries. (Credit to [[User:PiRSquared17]])
$(window).load(function() { $('.mw-enhancedchanges-arrow').click(); });

It auto-expands all the groups (as if auto-clicking all the arrows/triangles), in RC/Watchlist. I consider it integral/necessary.

Something like this, should be offered as an option in Special:Preferences#mw-prefsection-rc
and/or as a toggle-button in Special:Watchlist and Special:RecentChanges

Version: unspecified
Severity: enhancement