Hi mate, don't worry I didn't have any intention of trying to beat yours and doubt I could as the front end is way heavier than your carbon Lefty setup. Getting under 20lbs was always the goal and with the Furious Freds on it was just under but now I know it can then I'm going to relax it a bit for more useability. Likewise the SLR saddle is really cool but its an arse killer so I have a Fizik Alliante with ti rails which has a lot more padding and only adds ~ 60g so I can live with that but perhaps a matching KCNC scandium stem, lighter rotors, ti axles for the pedals ..... MUST STOP !
I did read up about the clamp type on the KCNC post with carbon rails and it seems that others have used it successfully and looking at the rails they are much thicker vertically so expect designed to take the clamp pressure and yes you can get a lower clamp assembly from Carbon Cycles designed for this very purpose.
I'll see how the XX brakes get on, so far they have been very good, better than the Juicy Ultimates for power and modulation but they do feel quite flimsy - not broken yet though !
It was interesting to try to lose 1.5lbs from the previous build and to compensate for the extra weight of the front mech, shifter, extra chainring and cables. The change to tyres and tubes over tubeless and the seatpost and saddle made the biggest drops. However, best of all is thanks to an outstanding bargain on the wheels and some good 2nd hand buys I actually spent less than I had previously. Result !