I suspect this is a known different/won't fix, but I'm tracking it anyway:

https://www.mediawiki.org/w/index.php?title=Help%3AExtension%3ATranslate%2FPage_translation_administration&diff=8349012&oldid=8343860

shows an edit I made to a template to avoid a use of {{^(}} which was intended to pass the string <!--T:1--> to the <syntaxhighlight> extension without the string being literally present in the wikitext.

I replaced it with <code>&lt;!--T:1--&gt;</code> which is 100% less magical, but loses the fancy HTML syntax highlighting of <syntaxhighlight>. I suspect the "real" solution here is to use out-of-band annotations (T424062), but there is perhaps something in the semantics of templates like {{^(}} which isn't quite captured by Parsoid yet.

This is from the user report in https://www.mediawiki.org/wiki/Parsoid/Feedback#Help:Extension:Translate/Page_translation_administration