As I said the only reason your example profile works even with <ref> tags after the <references/> tag is because you have the main citation before the <references/> tag.
The <ref> tags should always be before the <references/> tags and you have discovered probably the only way that they actually do what they are designed for even though they are in the wrong place.
It is still an error but more designed to pick up profiles like Young-26300 which just show a number instead of the source citation.
According to WikiTree styles and standards, the == Research Notes == section should be placed between the == Biography == and == Sources == sections. See the following help page:
Maybe I'm misunderstanding your comment ...
"unless members mistakenly used <ref> tags in their Research Notes"
Why do you consider it a mistake to use <ref> tags in Research Notes? I believe that there are good reasons to use <ref> tags in Research Notes.