Genghis,
Then, of-course, going around only once I'm absolutely certain I'll make it, which personally I take at around 50ft.)
This is an area where I found big differences between microlight and light aircraft training, as I assume you probably did as well.
In microlights it is usual to get very close to the ground before going around from a PFL, both during training and in the GFT. 50 feet or less seems quite usual.
On the other hand, when I subsequently did my JAR SEP training I was surprised to be told to go around at 500 feet, which is before it starts to get really interesting.
The roots of this cultural difference are obvious enough, since light aircraft engines have been generally reliable for several decades whereas microlight engines have only become so in relatively recent years.
I tend to agree with you that trying to preserve the pleasing aesthetics of a nice square circuit should not be top priority during a forced landing. Some of the techniques illustrated in the textbooks do tend to assume that you have all the time in the world to sort things out. If however you have been flying quite low (<2,500 under the London TMA example) in something with a high wing loading and a poor glide ratio then you're doing well if you can find a field and position for it at all, let alone fly a neat circuit around it.