Best Practices working in multiple Jira Service Management (JSM) projects

We have various IT units using JSM as their ticketing system:

ITS Service Desk (ISD)

CLAS IT (CSD)

SAIT Service Desk (SAIT)

BUSN IT (SBIT)

Engineering Technical Services (ETS)

Law Service Desk (LS)

To facilitate collaboration between central IT and distributed IT, we’ve given agents in the other JSM project permission in ISD similar to an agent role so that distribute IT personnel could look up ISD ticket, move tickets from their JSM instance to ISD, create tickets in ISD and read/add internal comment on an ISD ticket. Same permission is added on the distributed IT JSM project to allow ISD agents do same things in the other JSM instance.

The following processes should be followed when working in multiple JSM projects:

Ticket Transfer: Tickets received in a JSM project, where the service owner operates in another project, should be transferred to the appropriate project.
Multi-Project Work: If a ticket requires work that spans multiple projects, create a new ticket in the other project. Ensure that the tickets are linked, and the reporter field reflects the person experiencing the issue.
Make sure you are working on the ticket in an appropriate role (customer or agent). If you are not the service provider or assisting the service provider troubleshooting an issue, you should be a request participant on the ticket and receive public comments as the customer/Reporter on the ticket. Otherwise you should be a watcher (additional technician besides the Assignee) and add internal comment.