Will keep my eye out but Testbook and Rovacom are gold dust and kept very close to LR chest. The Rovacom as you may know IS the alternative.
Please keep me in the loop as I would love to help and test out on my RR.
Seen both on Ebay but extremely expensive.
Just thought!! My brother has an original Rovacom unit (sealed unit/all in one jobby). Can you extract all data from unit source.