Please guarantee that VPN will be up before ANY network access occurs

In my Kubuntu 20.10 system (network manager 1.26.2), and others, if I have set VPN to start automatically: I get notified first that Ethernet is up, then a second or two later, that VPN is up.

This make me wonder if there is any guarantee that VPN will be up before ANY network access takes place. Since I specified "automatic connection to VPN", obviously I want every single access to occur through the VPN.

Please provide some kind of policy statement or design goal somewhere that: If system is set to have "automatic connection to VPN", every single (non-local ?) network access will occur through the VPN client, at system boot time, login time, if VPN server goes down, anything. Every access must go through VPN, or fail.

Then, if needed, change software to implement that policy.

I first filed this as https://github.com/systemd/systemd/issues/17993 but was told to come here.

Thanks.