Yes, I believe so. IEC permits state that they cannot be extended, so implied status isn't valid for someone on one. Some people have been told by CIC agents that you can, but I believe there is documentation from CIC website that says implied stsus is not valid for permits that can't be extended (such as IEC).
I was actually totally unaware of this fact when I applied for a BOWP, well actually I was on my then spouses BOWP as a SOWP.. We both assumed implied status for a few months unknowingly. I only found out a year later!! Neither of us got caught, and we both have PR now.. however it seems we were ignorantly in the wrong at the time.
- btw I wouldn't suggest taking the risk just because of my experience. If we had known we wouldn't have kept working at the time.