I prefer the space between wheel and chocks not in conjunction with friction. As i mention above the parking brake is all i need and when she fails during high power you feel a bump when the wheels touch the chocks. It is like a wake up call to retard the throttle(s).
I think this is the correct reasoning for chock positioning fwd of the wheels.
I note the procedure don't specify a 'lookout' dedciated to warning of unexpected movement at all times...
4 engines at once saves time (but that's cynical).. once again, no lives lost thankfully
As for old farts being listened to... they should always be an integral part of operating procedures! - you don't get old by being particularly stupid
