HotNHigh
English proficiency for you, me thinks.
The sentence simply says adding the extra height and imposing an absolute minima are RECOMMENDED, read the whole of the section after recommended as just that - a complete section. I recommend you dont get too close to the edge, and I (recommend) you absolutely should not stand on the edge on one leg. If you like the recomendation that you impose a minima is a stronger recommendation by the addition of the word absolute.
That is the CAAs interpretation as outlined in writing on numerous occasions and one with which I would agree. You may not agree, but there it is.