I've installed MS on two e30 318is cars, my own (old setup, gone now!) and dan's. I now have MS2. I did not have any trouble firing the standard coils after I'd built the circuit correctly, I have COPs now. DISA and knock can be accomodated i'd have thought without too many probs, but I currently use neither. There's not a lot to worry about, MS works great with our engines. It is, of course, a very steep learning curve on any car, however. I never got cranking, afterstart or accel enrich as good as factory, I'm hoping MS2 will help in these areas. I drive the car on the lpg ecu quite a lot so the petrol ecu is mainly for warmup and performance, not cruising around. I've not done much work on MS2 yet, and am not driving around on it at the mo.
currently I'm more interested in getting the car nice and quiet which is proving difficult, i've decided m42s are pretty noisy, and mine in particular is pretty bad. prob is brand new cams/carriers etc are well expensive. i may change to an m44 head soon.