Two Identities in the Okta AspNet.Cookie

I have an app set up to use Okta as the identity provider. After logging, I can access the AspNet.Cookie and I can see the claims which all come from Okta. One of the Okta claims is a custom claim called customerKey. I use customerKey to get a much richer user object which I want accessible in the AspNet.Cookie, i.e. through the authenticaionManager. We have a large ecosystem that all depend on that cookie being available in there.

I have tried adding a second cookie. I see the cookie in dev tools, but the authenticationManager doesn’t know about it. I’ve tried adding a second identity. It disappears after a redirect to another page.

Is what I’m trying to do even possible? Any hints on how to accomplish this?