The Classical Extras plugin enables "Use release relationships" every time Picard is started up, even when the plugin is disabled.  I have to uninstall the plugin to keep release relationships disabled.

(I have verified that if I use the Picard UI to turn the setting off, that the Picard.ini file does get modified; that if I exit Picard, "release_ars" remains false; but once I open Picard again, it gets flipped to true.)