Hi,
as of my understanding, the local cache is the physically available and usable space for the appliance. 5x this size is the available cloud capacity. The logically cloud capacity is including all deduplication savings from the appliance and because of that the value is much higher.
Since deduplication is also working locally, you will be able to save more than 32TB locally, but never as much as in the cloud.
In general: Backup data gets written to Altavault, will be stored on local cache and gets almost immediatly written to the cloud as well.
Regards