Hi Harry, From another Harry and cyclocross racer, depending on what you have bought going tubeless was probably a good move ( though hardcore will still be tubular, but I prefer tubeless, less faff to put on and sort punctures)
If you started of with a fairly modern carbon frame not much else needs doing to it I expect.
You could go for a lightweight chain, I find they wear quicker though something like a KMC x11 SL weighs 242 grams compared to a standard X11 at 266 grams.
If you are running say 2 x 11 gears you could go 1 x 11 to save some grams. I run SRAM Rival , I once read a review that to go from Rival up to Force was only neccessary if you had money to burn.
Then of course there is wheels, how much do you want to spend? I stuck with aluminum wheels, hand built though at 500 quid a pair for strength etc. 3 sets all shod with different tyres for dry, mixed and muddy conditions. you can really kick the arse out of wheels, I know people with 6 sets , like me 3 different sets of tyres but they keep spares in the pits for those as well.
Other people have 1 set and will still kick my butt.
I have raced on and off for years and honestly in most races your bike will end up heavier as it will be covered in mud, lightening your bike by a few grams will make you feel more confident in the bikes performance maybe but it is really more about the rider.
I got rid of my old alu, canti braked cannondale and have a modern 1 x 11 specialized carbon disc brake beauty. The only thing that makes me faster on it is the brakes being better. I found I could not detect any advantage of tubeless over tubular ( but better than clincher as the first 2 can be run at lower pressures)
In conclusion you can throw money after more money on this but usually it is for a few races a year so how deep are your pockets?