In regard to NBP development there are several projects implementing Boot Managers able to offer boot menu extended features, scripting capabilities, etc.: Syslinux PXELINUX gPXE/iPXEAll the above-mentioned projects, when they are able to boot/install more than one OS, work under a "Boot Manager - Boot Loader" paradigm. The initial NBP is a Boot Manager able to retrieve its own configuration and deploy a menu of booting options. The user selects a booting option and an OS dependent Boot Loader is downloaded and run in order to continue with the selected specific booting procedure.

one more easy question :

cat /etc/nix/nix.conf | grep sandbox

sandbox = false
sandbox-fallback = false
extra-sandbox-paths = ```

while  

`configuration.nix` has 

nix = {
settings = {
sandbox = true;
};
};

How can I change the `sandbox=false` value in `nix.conf`to `true`

Thanks in advance for any indication.