Sitting at 6.58kg even as shown
I goofed a bit with the wheels. The old wheelset with tires measured at 2kg even. New 38mm deep tubular wheels weighed in at 1160g, and Tufo S3 25mms weighed in at 255g a pop (lower than specced weight!). Problem is I used Tufo's tape, which came it at 35g/wheel. So that's 1740g or -260g saved. Could have saved another 50g or so with Caden tape. Oh well. Mounting them was straightforward but murder on my fingers. Just had to take my time and make slow steady progress. Probably took an hour on each wheel from start to finish.
Other sources of weight gain:
ZTTO 11-34T -------> Ultegra 11-34T- ~+100g- I had to do it, the ZTTO is crap. The 11T gear is warped

And I just couldn't get it to shift right. Seems like the cassette is offset inboard, but if I space it out I can't get the lockring on. Ultegra worked beautifully with a quick RD tune up.
Cheapo cast iron bottle cage ------> +85g- I need to hydrate. I have some CF ones on the way which should save about 40g.
Wahoo ELEMNT Bolt + mount ----> ~+120g- a much enjoyed addition. Worth every gram, especially to protect my phone.
Still thinking of a path to get under 6kg without going exotic. Weight with 1 CF bottle cage and the Bolt not mounted (what I'll call "official weight" since I only ride with 1 bottle cage now) should be in the high 6.4s... call it 6.48kg
CrMo or w/e spindle pedals: -100g, 6.38kg
Cut seatpost: -30g, 6.35kg
FSA expander plug ----> Cane Creek EE plug: -25g, 6.15kg
That last 160g (to get fully under) will be a pain. I will have to look at my rides to see how badly I really need 34x34. I'm locked at 34T for the small chainring, but for my local roads I only need 34T on the back when I'm completely dead. Switching to a Dura Ace 11-30T would save about 120g alone. I would probably switch to a 44 or 46T for the big ring. So that would leave about 40-45g.... maybe I could switch to lighter tape? Again that damn Caden tape would have got me that much closer!!! Maybe some lighter stem spacers? I'm in the weeds at this point.
Just going to enjoy the bike for now though; absolutely loving it. It rides amazing. Only issue is the Extralite 50T shifts kind of finicky, which would be another reason to get a smaller big ring with better shift quality. I'm not ready to get a Darimo stem or w/e but I could rationalize something like a Fiberlyte chainring.
Anyway, here she sits:
