I've started using Firebase Dynamic Link to replace Google Short URL service. I see it allows only 5 custom domains per account. Is this limitation due to a free account that I'm using? Can I register more than 5 domain if I upgraded to a paid plan? Though, as per my best knowledge, Firebase Dynamic Link is a free product and doesn't have anything like paid plans.
I could not find this limitation documented anywhere in official site.
To know more about this limitation, I submitted a ticket to firebase support. As per reply, Yes, it's possible to increase the limit. You have to submit a ticket at https://firebase.google.com/support/contact/ with detailing the use case.
It seems they have not made this public but they can increase limit when requesting for selected Firebase Console projects.