Using surplus pre-dreadnoughts away from the battle line

If pre-dreadnoughts were already obsolete before 1914, what useful work could they still do?

They could guard ports and convoys and reinforce secondary theatres where cruisers and raiders could not safely challenge them.

In the fast-battleship counterfactual, additional pre-dreadnoughts would move into secondary stations rather than disappear from service. Their speed is poor, but a convoy protected by one becomes unattractive to an enemy surface raider. They could also guard distant ports and replace even older local-defence ships. More available hulls might alter operations such as Coronel by putting heavier British units in secondary theatres sooner. Fleet modernisation can redistribute older ships into useful deterrent roles even after they leave the main battle line.