Care would have to be taken to ensure that these blobs cannot be mutated via other means, or that a non-function blob can be converted to a function blob with p

Care would have to be taken to ensure that these blobs cannot be mutated via other means, or that a non-function blob can be converted to a function blob with passing through validation, otherwise it might be an attack vector, for someone to figure out the internal representation, and manipulate storage to forge one that trips up some fast-path code which makes assumptions about the input being correct.