I don't understand why the waveform limiter is causing the amplifier to shut down. The explanation of a "bad" waveform limiter is even more suspect when you were sourcing less than 120W from the amplifier. I am sorry but it just does not make sense to me.
Here are some critical questions that you may want to ask yourself as you work towards making a decision:
1. Am I happy with an amplifier that is rated 300W into 4 Ohms and is only capable of less than 120W into 4 Ohms? 2. If I am happy with 1, am I still getting good value for my money? 3. Do I trust Emo?
I feel for you as you try to resolve this issue but at least it's not a death sentence .