Isn't that a limitation of the implementation, which can be worked around by creating a new implementation with whatever licensing you want based on the format

Isn't that a limitation of the implementation, which can be worked around by creating a new implementation with whatever licensing you want based on the format specification? OTOH, a limitation of the spec cannot be worked around by any new implementation. (OT - isn't it generally recommended to compress before encrypting? Encrypting is CPU-intensive so the less you have to encrypt the better, also length can be a side-channel, and don't some encryption methods leak the existence of patterns in the source data which compression will eliminate?)