It does not only import addresses from a file, but enumerates them and distributes them into address groups, taking care of address group maximum sizes. In the end, a super address group will be created holding all addresses.
Note: as this is an "offline" script, i.e. without a live contact to the FGT, it will create a second script to delete all those addresses and address groups again. So, updating the content will need an import - delete - import new cycle.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.