Just going to pick up on one point which was incorrect
The I/O stated between Hammersmith and Barons Court there are 3 hoops which is correct but his comment about returning all signals to danger was incorrect. It would only put the inner home at Barons Court on the Picc which is X647c at danger not A647a or A647b
The District Line Information book, which is the reference document we train to, clearly states that all three signals return to danger - the I/O has in fact quoted the reference training material correctly.
If the Line Information book is incorrect it is that which needs updating, though I have a copy from 2001 which also states the same so I would question what you've said as we've been training that all three return to danger for at least 17 years.