While much of what you say is true, the ability to work as well in reverse as it can forward was very desirable in an express engine, even if not so much as in a goods engine. On arrival at certain termini, Euston or Lime Street for instance, it was common practice for the incoming engine to bank the empty stock back up the gradient to the carriage sidings. It was hardly reasonable to expect a Jinty or coal tank to take sixteen or seventeen coaches from a standing start up a 1 in 70 gradient. The train engine banking it allowed one to do this, but when 6202 was on the train, an 8F was commonly sent to Euston to remove the stock. Or so I've heard, anyway! There is also the problem of a possession en-route, where the train's running line might be under repair and wrong line working implemented. This would involve the train passing a trailing crossover, then the engine propelling it back through the crossover on to the opposite road. This would require the engine being placed in reverse, and could cause the Turbo not a little embarassment if she then couldn't get it to move!