Adding support agents who are non sell users as collaborators

For the business type we have and how we are looking to progress with our support and sell systems, it would be great for us if you provided the option to add a support agent to a sell ticket as a collaborator.

We do not want or need to provide them with a full sell license and this would mean additional cost to our business.

Or offer a 'light agent' options similar to support within sell so there is no charge and very limited access.