Alberich4

Yes, use a practical hedge with a nod to the regional style. They can be a bit arbitrary. The SOE style was conceived for the national competitions when a group of hedgelayers got together in the late 60s or early 70s to discuss how they did it and then decided on a style to which they could award themselves points. The point being it was a competition style, not necessarily what they did in the field. However it soon became the norm - fair enough in, say, the local National Park to have a uniform style and useful for teaching. As regards the Borders style: the reason that it resembles the SOE style could be that when the borders folk wanted to revive local hedgelaying, a group of SOE hedgelayers were invited up to show them how. Whether there was a recognisable borders style before that I don't know. It's not surprising that they are similar as they are both designed for sheep. Garden hedges should indeed be designed for the required appearance, unless you have livestock on the other side.

Freezing makes the trees more brittle and more likely to snap. True or false?

Styles are surely competition styles and only a rough guide for what should be done in the field. SOE style was set up by a bunch of hedgelayers who declared how they did it and an amalgamated and agreed style was set up for their competitions.