As you’ve noted, the \rules except wikilink pragma only applies to the current tiddler (and not any transcluded content). To completely disable ALL wikilinks in the current tiddler AND any transcluded content, use
\define tv-wikilinks() no
Also, if you only want to disable wikilinks for a specific portion of the current tiddler (and any transcluded content), you can use:
<$let tv-wikilinks="no">
... your content with <$transclude> widgets
</$let>
reference: https://tiddlywiki.com/#tv-wikilinks%20Variable
enjoy,
-e