Getting extra time in school is about MINIMUM standards. IE if your child just sneaks into the bottom end of the very wide 'average' band then they will not be eligible for extra time etc. Average is not the 50th centile. For example, my DS is on the 16th centile on one particular scale. The 15th centile is the cut-off btw 'impairment' and 'average' and so he is considered 'average'
It is not, as many parents think about enabling a child perform at the level that they might have done had they not had a SpLD.
As I understand it things have tightened up considerably recently. My son was recently tested for something else (than what I was referring to above), again he was 1 point above the very low cut-off and has lost the 25% extra time that they thought he was going to have. All the more frustrating as he suffers from multiple difficulties that compound each other but that is not considered.