The mazda is probably closer to the mitsubishi box - I have a Kawasaki box and it does not look remotely similar. Another point - JECS normally use low impedance injectors and have analog circuitry in the injector drive to pulse width module the current. JECS do the boxes for a lot of Nissans - they also like having optical sensors that they derive accurate timing from. The optics are the weak point as they tend to degrade over time.

If the Mazda boxes does in fact use a 6801 style cpu, you can be happy as getting the code out, whilst tricky, usually can be done. also, since there's not too much code, it is easy to disassemble. You also have the HC11 that you can port the code to and get more features in the hardware. Another useless fact - Ducati (magneti marelli) use a HC11 in many of their bikes. As for the latest models, I'm not sure of what they use. Delco also used HC11 and variants in many of their boxes.