"Using full reverse and max braking isn't going to be conducive to maintenance costs"
I think more in operational considerations than what the bean counters want. That said it wouldn't be that hard to make a case for LAHSO based on fiscal considerations. The money that is coming out of the MX budget is made up by the increase in revenue by the extra flights ORD is able to accommodate because of LAHSO.
"But an ATC assumption that any commercial air transport category aeroplane operator is automatically able to accept LAHSO is not"
It is incumbent upon the operator to advise ATC if they are not able to accept a LAHSO clearance. Usually done (per SOP) on initial check in with approach, otherwise ATC expects compliance with LAHSO as with any other clearance.
"but I consider that pilots should advise ATC that they are able to accept LAHSO rather than ATC assuming that they can unless advised otherwise"
Semantics. Either way, those who can accept the LAHSO clearance do and those who cant don't accept it. Doesn't matter if ATC' working on a default or positive acknowledgment. As I said most SOP's that I am aware of require declining LAHSO early on to allow ATC to go to plan B.
I see LAHSO clearances no differently than I see an enroute crossing restriction. Accept it if you can, decline it if you cant.