So looking at the board, this looks like it is for unbalanced stereo connections only? Is there a way to use it with balanced connections?
You are correct in that the LDRPot board as shown is for unbalanced stereo.
As with our current LDR.V25 Preamp Controller, to implement balanced volume control you need 4 channels, or 2 boards, with one board acting as the primary control interface which communicates to the secondary board to keep them both in sync.
I fully expect the final LDRPot design to be configurable for balanced audio. That will require a 2nd LDRPot main board with its own 2 channel LDR module be attached to the underside of the primary LDRPot main board. The secondary board will need 4 connections to the primary board; power, ground and a 2 wire serial data link. I'm hopeful those can be made with a direct board-to-board pin link but worst case you end up with a 4 wire square pin cable connecting the 2. Of course the secondary board will have its own screw terminal header for its own 2 channel balanced signal.
We have a few iterations to go through before the LDRPot is ready for release. We are developing the LDR.V3 Preamp Controller in parallel with the LDRPot where the LDRPot will be a simplified variant of the LDR.V3.