What is the best practise to build Safari Webpush for SaaS platform?

Hi Support,

Our product hosts a large number of e-commerce sites and the current Safari Webpush configuration requires a Identifier and Certificate for each site which is not scaleable. Is there any way we can implement with single ID or Certificate? And if we are to have multiple Identifier and Certificate, what is the limit on one Developer Account? Thank you.

Best Regards, Ronald