BRANZ (Building Research Association of New Zealand) have a free two page download called Post-earthquake Plasterboard Repairs. It is a digital version of the article that appeared in the August/September edition of their publication Build (No 131).
The article covers the problems associated with using plasterboard as a bracing element, the type of repairs that might be used, and the result to be expected. A very useful tool to check against what has been specified for your plasterboard repairs.
For Red Zoners who have been classified as a repair, comparing the repair method proposed by EQC or an insurer against what the article says may be a useful reality check.
As always, the issue is not about the most economic repair for the insurer, it is about what your insurance policy entitles you to.