Playing with a testing environment running VMWare Infrastructure 5.1, I noticed that only the node-level data is stored properly when storeByForeignSource is enabled (for the ESX and the VMs)/
All the data using custom resource types (i.e. generic index resource data) are being stored like if storeByForeignSource is not enabled (i.e. by nodeId), and of course, you can't see the stats on the WebUI.
Of course, after disabling this feature, I can see all the stats properly, so for now, we can't use storeByForeignSource with the VMWare Collector.