Hi Tim;
Apologize, just revisiting this issue now. Not sure if the link below will be of any help or not but figured I'd post it here in case you (or anyone else) may be looking for an alternative, perhaps easier, way around this issue using the Guest Agent. The link below identifies deficiencies with actual native Custom Properties not being called or interpreted correctly and offers a safe, intelligent way around this. Not sure why VMware hasn't recognized or resolved this so that these particular native properties could be made available for provisioning by cloning operations (perhaps there are indeed residual issues when using these during cloning??), but the workaround described certainly appears valid and is supported with plenty of rationale to substantiate the fix.
Ron
http://www.sovsystems.com/adding-machine-requestor-to-local-administrators-group-in-vra-7/