I don't really understand how that conflict is avoided. Do you mean services leaving the station from the high-number platforms can now wiggle across the throat, to get out of the way of a Thameslink bound for St P, because the reopened tunnel leaves somewhere else for inbound trans to get past them? But surely it's the new extra crossovers between existing tracks in, and just north of, the Gasworks Tunnel that allows for that, not the reopened tunnel? And in any case, presumably it all only helps in the case of certain combinations of platform use?