OK, thanks! Now I know, where to start.
In case anyone else has this problem, here's where I found what I needed.
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.
Hmm. That might make sense, maybe on plugin activate it appends to end and on deactivate it removes it
@psychobunny good point. 😆
Implemented in latest version of Lavender 🙂