I doubt this will happen anytime soon, if ever, but now the derogation conditions are met for almost all units, the 466 operating issues could be solved by doing the now smaller job of completing the refurbishment to full PRM compliance for just 4 units at first, over a couple of months or something, to stick those on the branch lines. Once that's achieved, gradually refurbish more of them to allow the first 4 more flexibility, solving shunting and formation restrictions and any other issues in turn. Not ideal, but better than keeping the derogation long term.