I couldn’t do it like that as the feed was to far from other side of the cupboard. I ended up cutting the tee out and replacing it so then I could do a pullover over the waste and send it far enough right. I also put isos on their for maintenance purposes.I don't like the 'up and over' plan in the OP, assuming I have understood it correctly, because (a) the 'mid air' section will be vulnerable to getting bashed when stuff is put in the cupboard and (b) it will make maintaining the waste-pipework harder. Have you considered just reversing the direction at the elbow so the ball-valve points downwards and is not obstructed by the waste pipe? You can also clip it properly so it's a bit more robust.
Reply to the thread, titled "Re pipe advice ??" which is posted in UK Plumbers Forums on Electricians Forums.