Hi,
If using EFI (UEFI) mode and setting NV variables, they go away if you power down the VM then power it back on. Be very nice to keep them, and then allow a reset option in the UI to reset NV variables back to defaults when needed. This way testing for that environment would be much easier when it relies on NV variables to ensure everything okay. As it is now, you can't reproduce test cases that need testing.
Thanks.