Thanks for elaborating your scenario here. We would like to have your application listed in Azure AD App Gallery. Consider this as equivalent to OneLogin's app catalog or OIN. This will help our mutual customers to easily able to add the app from App gallery ( all the gallery apps are certified by Microsoft) and then it will provide all the default values like URLs, claims etc. That way our customers have to only do minimum configuration.
Our process for listing the application in the gallery is available here https://aka.ms/AzureADAppRequest I own this program in the product group. So feel free to reach out to us if you have more question using this email alias SaaSApplicationIntegrations@abdou .microsoft.com
Note that we are not part of Partner Center yet but we have our own process of listing the applications in the Azure AD app gallery.
Thanks,
Jeevan Desarda