Floating Decoys

[mmacguinness]

CMO appears to treat EW Successes by Floating Decoys as clean misses.

Yet, is it not to be expected that an ASM that has been spoofed by such a decoy would actually impact the decoy or the sea in close proximity to it?

In my limited experience, that is exactly what happens.
In 1987, I worked on upgrading the oil piers in Kuwait when the Iraqis were firing Silkworms down along the Kuwaiti coast. The Sea Isle City tanker was struck while coming in to load at one of the piers. Later, the Sea Island loading platform several miles offshore was struck by a Silkworm. Damage was minimal because the Iraqis had reduced the warhead weight to increase the missile's range.
After that, barges with large triangular aluminium radar reflectors were anchored at several points around the piers at a distance of approximately 500m.
The decoys worked. The next Silkworm, in early 1988 as I recall, struck a decoy instead of the pier.

How far from the ship would a floating decoy likely be when struck?
Could it be close enough to cause blast damage to the ship?

CMO does model blast damage to ships from Kinzhal near misses, but not if they have been spoofed by decoys, e.g:

11/1/2023 6:03:02 AM - Weapon: Kh-47M2 Kinzhal [700kg HE Penetrator] RV #4260 missed DDG 60 Ramage by 374ft
11/1/2023 6:03:02 AM - [USN] DDG 60 Ramage has suffered blast damage: 43.4 DPs