Well, I did my single engine add on in a TB-9. However, the Multi was done first in a PA44 and that demonstrated I knew how to fly a complex aircraft. Also, on my CFI checkride, I had a mecahnical issue that made me decide to end the flight early. I grabbed a normal 172 after parking the gutless, preflighted, and did a power off 180 to finish up.
As for your original question, I don't know. I've never heard of anybody doing it in anything other than a complex, and personally I'd rather do everything in one aircraft. Using different types on a checkride means twice as much work on systems, and twice as many places to screw something up.