On many restrictive networks, Proton's default endpoints have been blocked even if the protocols haven't. The other platforms that Proton VPN runs on have the "Alternative Routing" feature, where the application connects you through a different endpoint if the default one is blocked. However, on Linux, the default *.protonvpn.net endpoints are used no matter what, which are easily restricted.

Adding this feature would mean users would be able to use the Linux client on networks that block the standard Proton endpoints.