Plugin Ownership
You're now well on your way to a healthy Backstage instance! It's been launched to the whole company and you're loving the feedback developers are giving you. Some developers have even started broaching writing their own plugins.
Inner source
Accepting internal contributions from other teams is a good sign that you are on the road to a developer portal tailored for your developers. This is a well paved path with many upsides, but a few downsides as well. As your Backstage instance grows in size and age, those same developers may be difficult to find. Your team may start to experience more and more struggle updating Backstage.