Right now machine-readable op mode outputs use the same units as human-readable ones — usually megabytes or adaptive units (32K, 100M, 1.2G...). That hurts machine-readability since machine clients must parse those units, or even guess them if units are not specified.
For consistency, we should always output data amounts in bytes to machine clients and leave them to do their own conversion if they want to show values to users.
It's "perfectly compatible" for now since machine-readable op mode isn't in any stable release yet.