We should always remember that circuits present an astonishingly high perceived workload to the average student. Once circuit training has begun, he/she needs to plug away at the exercise to benefit from the continuity of the landing phases. In my view, it's not a good idea to stick in other exercises at this point. Sufficient, perhaps, to point out that, if the motor does stop at circuit height, pointing into the field offers the best chance of walking away (usually).
I know what BEagle means about 'bomber' circuits but we also have to remember that schools operating at airfields with mixed traffic are constrained in this respect. The trick is to ensure that Bloggs knows that one size fits all is not the case and the instructor should ensure he/she has experience of busy airports and whizzy GA fields,wherever possible.