Regarding the imposition, naturally this becomes a big issue on a full flight with other problems thrown in. The worst aircraft and configs are the 777 three class with ten crew and the High J 747's.
Fortunately I have been around long enough to have seen this all before. The current management regime think they have reinvented the wheel with all their cost cutting. In a year or so's time, they will have to put the crew back on if they still want to have an airline that regards itself as a "premium" carrier. Of course things would not be so bad or noticeable if BA had only cut back on the crew, but the product has also been decimated. This double whammy will have our Exec members leaving BA in droves as in their eyes, BA are simply taking the piss.
On the full flights I have operated, I have been lucky that there have been no AVOD problems, safety/security or medical incidents. But it will happen one day. The only difference on busy flights is that the service takes longer in Club.
I have no problem with BA taking another crewmember off, or even two, but the busier the flights are, the more the crew reductions impact on the service. Just simple arithmetic really.