I checked with my IP team contacts and confirmed that it not possible in this version of InfoPath. The special InfoPath folders are only possible with client-only InfoPath forms folders.
The workaround is to manually create an InfoPath form folder, manually configure it to use the form you're syncing, then select all the sharepoint sync'd forms and Edit::Copy / Edit::Paste those into your folder. You'll have to manually keep them in sync but it will work to promote the properties.
Thanks, Shiraz
Shiraz Cupala / Microsoft InfoPath MVPQdabra® Software / Streamline data gathering to turn process into knowledge