Hi,
I agree with you, each domain should have its own portal. However, if there is a way to have more flexibility, I would let the user choose. Maybe we could have a SSO configuration page where we could create portals and assign domains and subdomains to them. (But I have a feeling it would be a scripting nightmare)
My reason is that I am a cheap guy with only one domain. I have the issue with three YNH instances sharing this same base domain, each with their own subdomain. See my previous thread where you helped me.