23.35 is light for a 29er no?
Wheelset gives the most advantage IMHO. Merlin Hope Pro 2 Evo + Crests = £350? Less yours on ebay = £260 net?
Replacing something that is worn out for a lighter version is much less expensive so a XT 32tooth cassette when your present one wears will save a fair bit and only cost you approx £15more? If your saddle isn’t comfortable a lighter Kium Gobi probably will be and lighter too. Ebay the old one and you might be £55 out or so.
Carbon bars and foam grips have a comfort benefit too so money spent here gets double use as does a carbon seatpost though now it’s starting to get spendy. Eastons EC90 SLs £90, esi racers £15, USE carbon Sumo £80 You can ditch the gear indicators too.
A lot of weight in 520 pedals.
Lightweight inner tubes save 75g each if you’re carrying them as spares. If you carry a couple then that’s 150g for approx £16 (continentals)
WW = ££££££. For all that expenditure you may save a pound in weight. Me I’d replace the cassette, grips, saddle if it’s uncomfortable and carry lighter tubes while plotting the super weeny build (for which you may have the right frame!)