I think they have used the same D3 machine with a new controller to mine a different algo.
Does any one have Both A3 and D3 ? I wounder what will happen if you connect D3 hashboard with A3 controller.
Controllers and all observable software / firmware are identical. If they are the same miner the change was made at the ASIC / PIC bootloader level which will take quite a bit more work to figure out, let alone figure out how to move algos. It will likely not happen even if it is possible. This is coming from someone who has already torn their A3 apart software and hardware wise to find out.