For those who decide to “repurpose the foam” from cartons that the mounts were shipped in, I thought I would mention the easier way to cut any foam to the shape of the new case.
The idea offered on the web, was to first soak the foam in a tub of water, then place it in a home freezer, until it becomes a solid block. You might be able to use the emptied freezer section of your kitchen fridge, if the foam block is small enough. Otherwise, you need to have a floor sized freezer, or ask to use a friend’s. Shouldn’t take long before the removed food begins to thaw and needs to be put back.
Once you remove the solid foam block, simply use a “saw blade” to easily cut the foam to size.
This saves the hassle of the foam “squirming around” resisting a thousand cuts. If it is frozen, and you are quick at sawing, it would be as easy as cutting those hard white ornamental crafts blocks, and the end result would probably look much smoother, rather than something hacked.