Allow More than 5 Custom Domains on App Runner

I am going to host an application that receives HTTPS requests from thousands of different domains (actual root domains and not just subdomains).

However, App Runner only seems to support up to 5 custom domains (based on documentation) and there does not seem to be a quota increase request for that.

Is it possible to increase the custom domain limit?

Start with the AWS App Runner documentation on custom domains and service quotas, focusing on the stated five-domain limit and whether a quota increase request exists. Done means the issue has a confirmed supported limit, an available quota-increase path, or a clearly documented product change request.

Written by the indexing model from the issue text.