Ian W ...
Good point about the search costs! I am doing calculations in that field. Quite complex, because quite a few assets and resources have multiple uses and applications.
Against that we have the relatively cheap fixes for the problem which from an engineering viewpoint are trivial.
A prudent design approach for commercial aircraft, in my view ( based on my experience ), is to start with saying that "nothing in the design of commercial aircraft is trivial". Even very small and apparently insignificant changes can be very or even extremely costly. There are thousands of examples for that. You do not add anything until you can really make a case, and make that case to 'all specialist directions' and 'stakeholders'.