Rigga,
Appreciate your argument, but I'm afraid that 'using BDR techniques' to install new systems is just not on, whatever the reason. You can do it properly and fast - it's getting the agreement on what 'fast' is that's the trick.
Not enough time testing (and training) and people end up getting killed for no good reason. I had to pick up the pieces (literally) once or twice and I remain angry and disappointed at the people who failed in their professional duties on these occasions. I'm sorry to say that their reasons (actually excuses) for doing things to aircraft that were unsafe were the ones you are getting near to using.
I don't think I said that RAF engineering was led by donkeys. I rate RAF engineers very, very highly, especially at Chief tech level, and also further up the tree. My concern is that there is an institutionalised culture in that service that 'the pilots always know best' and 'must be given what they want'. Sometimes, you have to say no. I was lucky enough to be allowed to be an FAA engineer, and allowed to say no, and backed up when I had to. And here's the nub - it was the pilots who backed us up.
Best Regards as ever
Engines.