How to set or get deduplication time on Sandbox?

Also will it behave the same while running with/without persistent ledger?

It used to be possible with the CommandConfigurationService, but as we transitioned to a different architecture, having a participant node dictating deduplication rules for an entire network around a ledger made little sense. For the sandbox, I’m not sure whether there is a switch to adjust it when starting up the sandbox.

If the switch I mentioned before is available, the deduplication will behave the same way, with the important caveat that a persistent sandbox will be able to retain deduplication information across restarts.