Do you mean the installer that is downloaded from the customer support portal such as BeyondInsight_25.1.1.165.exe? Yes this is used for performing a manual upgrade of BeyondInsight/Password Safe especially for customers who are in air-gapped environment and not using the BTUpdater.

​@Howard Thanks for Info. Yes, Installer like BeyondInsight_25.1.1.165.exe downloaded from support portal.

Not only for the upgrade, Can this also be used for a fresh installation without using the appliance VM?

We don’t support BeyondInsight outside of our appliance as there are hardening, configuration in the appliance. Even if it’s a development environment customers are still required to purchase an appliance an a valid license.