In https://classic.tiddlywiki.com/#[[TiddlyWiki Browser Compatibility]], mention that the opera:config#UserPrefs|AllowFileXMLHttpRequest
option is actually for Opera 12.x and below, while --allow-file-access-from-files
is not only for Chrome but probably also for all Chromium-based browsers (confirmed here for Vivaldi, new Opera, Opera Neon; to be tested with Chromium itself).