Oh, I see what you mean. It usually needs calculating centroids and Insights doesn't do it at this time. Please submit an idea with your use case(s).
The best approach would be to have the centroids precalculated as a separate layer. If you don't wish to duplicate attributes just have a field that you can join back to your polygons. This way, you can use Joins within insights to create a single dataset that has both polygon and point geometry.
Thanks,
Akshay Harshe