Hmm ... where exactly in the epub 3.2 spec does it say that?
I was looking in the latest version of 3.2 in the section on obfuscation here:
https://www.w3.org/publishing/epub/e...ce-obfuscation
That entire section only ever uses font examples when it talks about resource obfuscation.
If you are correct, then that is a backwards incompatible change between the epub 3.0, epub 3.01, and epub 3.2.
That plus the fact that epub 3.2 spec says it package version must report "3.0" (something they have not thought through well or some part of the spec that they forgot to change) means there is no easy way to detect between the two cases. And character data that is not compressed first (unlike binary font tables) then obfuscated (to meet the new 3.2 spec) is pretty worthless.