Still looking but this may be an edge case because of script / syntax error on the page which prevents the "{{Documentation}}" string from getting tokenized properly in the PEG which then causes it not to be displayed.

Ah, looks like the issue is more about <includeonly>foo<includeonly>bar</includeonly>baz<noinclude>xyz</noinclude> as seen on this page. Looks like with legacy output, it matches the </includeonly> with the outer <includeonly> whereas Parsoid seems to match it with the inner <includeonly>.

Maybe Parsoid should have the same error handling.

In T372675#10074599, @ssastry wrote:

Ah, looks like the issue is more about <includeonly>foo<includeonly>bar</includeonly>baz<noinclude>xyz</noinclude> as seen on this page. Looks like with legacy output, it matches the </includeonly> with the outer <includeonly> whereas Parsoid seems to match it with the inner <includeonly>.

Maybe Parsoid should have the same error handling.

The test page was fixed by T373776 / Ied9ed72be7bbff6d7f323109bc0043f1aa0f4b70 and renders the same now.

I wonder if we should just fix the wikitext and call it done.

The diff that remains is another issue that needs investigating

The docs render the same,
https://shn.wikivoyage.org/wiki/%E1%80%91%E1%82%85%E1%80%99%E1%80%BA%E1%80%B8%E1%80%95%E1%80%9C%E1%80%B5%E1%80%90%E1%80%BA%E1%82%89:Wikidata_Infobox/doc?useparsoid=0
https://shn.wikivoyage.org/wiki/%E1%80%91%E1%82%85%E1%80%99%E1%80%BA%E1%80%B8%E1%80%95%E1%80%9C%E1%80%B5%E1%80%90%E1%80%BA%E1%82%89:Wikidata_Infobox/doc?useparsoid=1

but when included on the template page (ထႅမ်းပလဵတ်ႉ:Wikidata_Infobox), it results in two nodes on the page with the same id, wdinfobox.

If I look at,
https://shn.wikivoyage.org/wiki/%E1%80%91%E1%82%85%E1%80%99%E1%80%BA%E1%80%B8%E1%80%95%E1%80%9C%E1%80%B5%E1%80%90%E1%80%BA%E1%82%89:Wikidata_Infobox?action=info
I see,

Duplicate IDs	1

https://shn.wikivoyage.org/wiki/%E1%80%91%E1%82%85%E1%80%99%E1%80%BA%E1%80%B8%E1%80%95%E1%80%9C%E1%80%B5%E1%80%90%E1%80%BA%E1%82%89:Wikidata_Infobox/styles.css would need to be updated to use a class before updating the template

https://shn.wikivoyage.org/wiki/%E1%81%B6%E1%80%AD%E1%80%AF%E1%81%B5%E1%80%BA%E1%82%89%E1%80%90%E1%80%BD%E1%81%BC%E1%80%BA%E1%80%B8:%E1%82%81%E1%80%B5%E1%80%84%E1%80%BA%E1%80%B8%E1%81%B5%E1%80%BD%E1%80%84%E1%80%BA%E1%82%89%E1%80%9E%E1%80%84%E1%80%BA%E1%80%90%E1%80%AE%E1%82%88%E1%81%BC%E1%82%86%E1%82%88/%E1%80%91%E1%82%85%E1%80%99%E1%80%BA%E1%80%B8%E1%80%95%E1%80%9C%E1%80%B5%E1%80%90%E1%80%BA%E1%82%89:Wikidata_Infobox doesn't show any use so maybe I'll do that