Have a read of the HO guide on firearms security. It should answer most of your questions and you’ll then be able to justify your decisions to your FEO based on that (should they be difficult).
Asking isn’t a bad idea but be aware that they may “gold plate” the requirements and then you’re in a difficult position having already asked them what to do if it’s unnecessarily difficult and contrary to HO requirements.
From recollection, floor mounted is ok but the bolts have to go into the joists and not just floorboards. As others have mentioned, they don’t like locations that are so difficult to access that you may be tempted not to use the safe.
Asking isn’t a bad idea but be aware that they may “gold plate” the requirements and then you’re in a difficult position having already asked them what to do if it’s unnecessarily difficult and contrary to HO requirements.
From recollection, floor mounted is ok but the bolts have to go into the joists and not just floorboards. As others have mentioned, they don’t like locations that are so difficult to access that you may be tempted not to use the safe.