Using Congregate for Piecemeal Migrations

Hello,

I am inquiring concerning the use of Congregate for piecemeal migrations from a GitLab self-hosted instance to GitLab.com. I noticed that according to the documentation located here https://gitlab.com/gitlab-org/professional-services-automation/tools/migration/congregate/-/blob/master/docs/using-congregate.md#quick-start that a command to populate a .json file with all repository information and MongoDB entires is achieved with ./congregate.sh list If I have a self-hosted Gitlab instance with 95,000+ repositories, is that command needed and if so will it proceed to copy everything from the instance into the container that Congregate is running from? Would there be a way of migrating projects from a larger instance like this using the utility that side steps this command and imports only a few projects at a time with associated groups/users without pulling everything in at once perhaps?