Futaba can guarantee only that their receivers will work with all of their other types of equipment. All current Futaba receivers will work with all current Futaba transmitters, given that the same channel and modulation type are used on both units. Futaba cannot assure you than other manufacturer's equipment is compatible with their equipment. That would be up to those manufacturers.

The synthesized RF module used in the 9Z transmitter does have a slight difference in its signal that some non-Futaba receivers cannot properly decode. This is not a problem with any Futaba receiver.