To provide a bit of additional public info, the new Laserfiche self-hosted subscription tiers have options for "Sandbox" environments with separate primary licenses so you can have non-production LFDS instances. Per the Laserfiche Pricing page, the Business subscription tier includes Sandbox testing environments. If you're on a different subscription plan that doesn't include Sandbox environments, your Solution Provider can discuss options with their Laserfiche Regional Manager like Miruna suggested.

Option #2 that you listed will not work technically as most applications licensed through LFDS have strict connectivity requirements to it for security and authentication. Most will not even start (or will do so in a limited state) if they cannot connect to LFDS to validate their licenses.