4.2.0 is bundled into the current build of Fusion10:
ovftool --version
VMware ovftool 4.2.0 (build-6230482)
This version has a busted --allowAllExtraConfig flag, so some VMs will not export to OVA, instead you get a slew of errors like this one:
- Line -1: Unsupported value 'disk.EnableUUID' for attribute 'key' on element 'ExtraConfig'.
