If one's argument is that thick bags delay boarding (per lensman's post), then it really doesn't matter whether the offender is flight crew or a pax. A delay is a delay.

In my case, the FA was blocking boarding as she struggled to stow her bags. However, it was quickly resolved once I assisted her. I made no negative judgement of her voluminous baggage since I assumed she was exempt from the rules. I just wanted to get things moving, so I helped her.