SOLVED

In case anyone else has this problem, here's where I found what I needed.

File: /nodebb/src/controllers/helpers.js
Methods: buildCategoryBreadcrumbs and buildBreadcrumbs

Editing those allowed me to get the behavior I was looking for. Although, I would be curious to know if there is a better way to do this without changing the source code.

Yes, set it as a child category of another, then remove the relationship to correct the issue.