The 3 way cavity tray is as good as expected, in fact it us very good! It is now installed along with three others along the back wall of the side extension.  The bricls arerogressonghere also.  Soon be time to order roof trusses. Will probably order sun tunnels from Velux at same time.
No photos, slight mishap befell mobile phone,  a scaffolding board fell on it, well really only half a scaffolding board, but the effect was the same! Going to call ee tomorrow and negociate a new one!