One a Whim, I just purchased 2 of them. I really can't see how or why WheelTop would change their internal derailleur programming to only work with a SRAM Cassette. In order for the limit set screw adjustments for the low/high gear/cog to work properly, they still would need to be able to fine tune the derailleur cage position relative to the highest gear on the cassette.
Perhaps the store selling this combo doesn't know or want to advertise the phone app that will let you adjust all of the features that the derailleur offers.