That sounds an ideal way to go nervousmom. I wish my DD would have listened, but I cannot fault her as we did not think to practice such an approach.
Next time for DD2, I think we will put it some practice doing it that very way. It was too much (and a lesson learned) to just expect DD1 to execute a similar approach Without practice.
We assumed that because it was multi choice it would always be just A-D (and a 25% guess success rate) but partly because none of the practice materials had anything different to that and Walsall did not throw up anything different!!!
If I have understood things rightly though, In some sections guessing gives you just a 10% chance of a correct guess, so whilst every little helps, CEM seem to have a strategy to minimise (but not eliminate) the potential impact of guessing.
The guess all remaining answers at the 1minute call was new to me until recently. With my previous sitter I took the keep working approach assuming one or two left unanswered at the end of a section would make little difference better to get one, possibly two guaranteed extra marks. However due to the ridiculous timing involved with CEM it is often not one or two that are left but almost half a section. When it comes to the borderline area where there are a bulk of marks getting one or two lucky guesses could edge DC into the yea rather than nay category. I agree that having short sharp sections negates some of this last minute guess work strategy but sensibly time tests would be a better way forward.