Should I deindex subdomains to prevent index bloat?

Hey guys,

I'm following this case study to fix index bloat on a SaaS website. I'm at this part that says to check for www pages crawled and indexed when you serve non-www pages (and vice versa). Our site hosts a SaaS tool and I discovered that there are thousands of non-www pages indexed that are mostly clients' log-in pages.

These are subdomains that our clients use in order for their users to go and log in to our SaaS tool from their websites.

Let's say that we have a client called example.com that integrates with our SaaS tool. To allow their users to utilize our tool, they have a "Member Login" page on their website that redirects them to a subdomain of our website that's example.oursite.com which is a Login portal. So there are thousands of such pages indexed that IMO don't need to be in Google index.

What's the best way to fix this given the fact that each client's website passes link juice to our domain thanks to the current configuration?

Thank you! :)