I was just wondering if you got your Rover tandem yet? Ultimately I hope to convert my single Rover into a tandem, and get another folding trike for me. My wife already has a Traveler. We travel for a couple of winter months most years. And while I can transport my Rover assembled and Nancy's folded Traveler, at the same time in our Toyota Prius V, There is little room left for packing camera, birding gear, and luggage. Hence the need for a second folding trike... or a hybrid van?!
You guys should consider attending TerraTrike's RiderFest just outside (west) of Grand Rapids, Michigan. The event is July 29th. If you were to let the folks at TT know you wanted to test ride a Rover tandem, they would probably arrange for one to be there.
I wanted to mention that I put a Bafang BBSHD electric assist motor on my Rover with the thought of using it with the tandem when there was a weaker (than this 67 year-old) rider on the back. This might want to be something you folks want to consider.