Switch Front Derailleur to SR
People usually install a steel Chorus front derailleur when the non-replaceable carbon carbon cage on their Record or SR derailleur breaks. It's not worth a handful of gram savings.
You've got it the wrong way round mate, chrous FD is stiffer than SR.
Weight differences only really matter in the kilo range. There's no point spending hundreds of dollars on functionally identical components to save 150g (unless you like how it looks or whatever). Work out how you can cut at least a kilo off your bike, then spend the money.
Best way to get half a kilo off easy is to just to buy tubs... but the trade off is tubs are a PIA - your bike will feel snappier, but you'll have to lug a tire around in your jersey which kinda mitigates the weight savings you just attempted to make... then you have the fun times of trying to remove a properly glued tire on the side of the road and gingerly rolling home on an unglued tire... followed by the 24hr minimum process of re-gluing a new $60-120 tire (which, according to Murphy's law you'll flat on the second ride because you didnt age it, properly pre-stretch it and take your time letting it settle on the rim because you got frustrated by doing it properly the last time)...