If you looked at the rules very strictly then one of these would be allowed right? Provided it is USCG approved obviously...
If that's a Type V PFD, then:
in order to count as being on board, it must be worn, and
the wearer must be 16 years or older.
Inflatable PFDs (especially automatic inflation PFDs) are not a popular choice for catsailors. They can inflate at inconvenient times - such as if you get teabagged, or snag the pull-tab on a shroud. They also need more maintenance and must be rearmed (at additional cost) after activation.
