We currently have Disagg running in leader, follower and switch modes in tets/format. Now, we want to extend the test/format to support multi-mode. 

The overall goal is to have multiple databases with multiple connections, where one acts as the leader/primary and the others act as followers. PALM should be used to manage checkpoint reading and uncheckpointed data, ensuring this information is communicated across leaders and followers.

The exact approach for this is not yet determined. This ticket covers:

1. Investigating how this can be achieved
2. Creating a clear implementation plan
3. Implementing the required infrastructure

Any testing-related bugs discovered during this process should not be handled in this ticket.