State organization differs from registry organization

We have two Terraform cloud organizations. One is hosting states and another hosting registry. We would like to use Team tokens to access state and registry modules.

We found a way how to do it. We specify in terraform.rc config file (holding registry team token) credentials for registry and use -backend-config option to pass in state team token. This approach works. Is it possible to do this using environment variables?

TF_TOKEN_app_terraform_io can be used for registry/state in same organization. Does it mean that using two organizations is total misconception?

Is there any posibility to share the registries in Terraform Cloud like it is possible in Enterprise version?