At first, you should define something like a service level agreement
or a backup/restore concept with your customers.

My company defined this on a day base ('unlimited number of
versions'), but we can't tell you how long to keep YOUR data, and when
to make the back-up.

In general, you can define incremental backups of all files/filespaces
on a daily base, avoid selective ones. If you want to make additional
backups for keeping the backup for years or so, you SHOULD NOT use
various inclexcl files (or you should use different nodenames for each
set/inclexcl file), you can use archives.

We only use sharedstatic copygroups to avoid inconsistent backups, and
we exclude every file which is usually open at backup time.

For the exact definition, RTFM.

Just my cents

Roger Hohmann