A few years ago, I spent quite a few hours instructing in a Seneca II, mostly "beginning" multiengine students. It can certainly be done, our standard procedures were to make sure that power had been reduced slowly to some lower-range setting prior to any engine-out simulations. Kind of takes the surprise away, but, a wiley instructor can still come up with realistic scenarios. A full-power V1-cut type of drill has got to be pretty harsh on the turbos, I seem to recall that maybe one of those per student during training was deemed appropriate. I don't remember any particular increase in maintenance issues, but, at the same time, was very glad those weren't my TSIO-360's!
So, turbo- anything is not particularly ideal for training, especially for multi- practice where engine-out is the whole point, but, it can be done. I sure wouldn't go out and buy a II for the express purpose of multi- instruction, but, if that's what you have, it can be done.
