Version byte mismatches are ignored as of #412
CPL validation relies on regXML to extract MXF descriptors, and regXML does report a Warning in case of unexpected version bytes. However, that Warning is reported for the CPL, rather than the MXF asset directly.
The MXF parsing/validation code would require a refactoring to report anything but fatal errors (via exception). Should be revisited as part of a larger MXF cleanup/refactoring.