Is there a minimum or maximum partition size ?

The minimum partition size of 5MB. Partitions smaller than this should use the floppy disk version.

The standard version of PFS-2 has a 2GB partition limit and a 4GB drive limit.  No such limits are imposed by the direct SCSI version.

4.2 (17.8) Introduced TD64 support to break the 2 and 4GB limits detailed above.