Perhaps, you can use the Package Deployment to help with K2 role creation. I'm assumed that you make use a lot of K2 roles in the environment. However, adding users to K2 roles is still done manually. I would make a suggestion to https://ideas.k2.com/ to bring to the attention to the developers for a chance to see in a future release.
Environment A (Source)
1. Create a generic workflow with Task event/step.
2. Add K2 roles as the destination.
3. Publish the workflow and create a K2 package from it. The package will automatically add K2 roles under Addtional Items (Uncategorized).
Environment B (Target)
4. Deploy the package from step 3 to environment B and confirm the K2 roles are created via Management site.
5. Add users to the deployed K2 role from step 4.