Hi David
As of now PCA is the only standard SAP tool to do delta queue cloning and there is no other way to do it.
Even BDLS cannot convert the queues from one logical system name to another.
If you don't have LVM/PCA the best way would be to "empty" the delta queue by updating all data from the source system to the BW system right before the upgrade. Then you can connect the new upgraded system to the "old" source system, do an init without data transfer and you can continue where you left off.
The only catch is, that no new delta shall be written to the delta queue until the upgraded BW is not connected to the source system.
br
Roland