Is there a minimum or maximum number a universe size has to be in order to accept it as a project?

There is no limit on the number of records that can be loaded into a COS project.

However, unique situations may arise that require the data to be loaded separately into the same project or split across multiple projects.

Each individual data file has a 250 megabyte load limit. If the file size being loaded exceeds this limit, the file will need to be split into multiple smaller files, with each one loaded into COS individually.