When you come to use SWPM for the first time to copy a SAP system which has a virtual hostname defined and used, be aware that the SWPM has in-built checks to ensure that the Windows registry is correctly configured according to SAP note 1564275.
If you've not fully implemented the note configuration in the Windows registry, even if you're using the "SAPINST_USE_HOSTNAME=<hostname>" SAPInst.exe parameter, the SWPM will show an error and exit.
My specific setup was missing the DisableStrictNameChecking setting. After adding this into the registry, I was able to launch SWPM.
If you've not fully implemented the note configuration in the Windows registry, even if you're using the "SAPINST_USE_HOSTNAME=<hostname>" SAPInst.exe parameter, the SWPM will show an error and exit.
My specific setup was missing the DisableStrictNameChecking setting. After adding this into the registry, I was able to launch SWPM.