I'm looking for a way to extend the existing property type PropertyLinkCollection (or "Link collection" in the GUI) but it seems a bit cumbersome to me. What I want to do is to add a bool variable that should be rendered as a checkbox for each link in the list in the editors GUI. I guess I can add a new custom property and make it extend PropertyLinkCollection and adding my bool. Does that seem like a good idea? Could anyone give me some hints or tips on how to do this?