well, if it makes anyone feel better, our epicyclic chip detectors were checked every 25hrs previous to this happening, so if it means doing it every 10 now, then its no great hassle to do this. it takes literally 10 seconds to check, so could be done on every turnround if that is what was mandated, without any impact on sheduling/operations.
i for one as an L2 engineer, amoungst other aircraft, would happily carry this task out after every flight if it helped to allay the fears of those flying on the A/C.
one other thing about the HUMS though, that i dont think anyone mentioned. when you fit a new component that has a threshhold, they often have to be re learned due to differences between the items fitted. no two are exactly the same.
pulling greaboxes in the circumstances laid out in the SB, thats going to put a lot of pressure on the Engineers, but alas is something we'll just have to get on with. sourcing gearboxes will be a nightmare. spares for overhaul arent easy to come by. It takes two years for an epicyclic ring gear to age harden so there is a massive lead time needed for spares support on them! same for a main rotor mast.