Tried the commute home via the Metro Tunnel and it looks like the gains are negligible.

The trains were timely: both the one I caught from Anzac, and my connection at Melbourne Central arrived when I reached the platform. But I felt that I got lucky here. And I ended up on the same train out I would’ve caught if I went my usual route.

Furthermore, I felt I got lucky with road crossings, and if I missed the one at Kings Way, I would’ve missed both trains.

So no, it’s not viable. Too many lucky arrivals just to get me on time with my usual way home. A decent alternative, but it won’t work for my main commute home.