I took a risk and ordered it in UD glossy size L. If the Mikeyblue with size S has 1168gm, I hope that L size should have 1250g max. I also asked Kitty from Winow and she wrote "The weight has been optimized and is lighter than before" but she does not wrote me specific weight.

Cool, same as me, most of the things you planned to do I also have on my list.
The Overfast Thru Axles however I couldn't get my head around to spend 200 bucks for a weight saving of 34 gram, not sure how you get to shave off 60 to 80 grams there. My axles that came with the frame are together 64 grams and the overfast axles are together 30 grams. The titanium axles are also around the 240 dollar price point but a little heavier (40grams). What I did was checking for myself, what I think, what is still affordable grams to price ratio. So, in the end I bought the alu axles with dropout, which reduces it with 16 gram (from 64 grams to 48 grams) but costs (50 dollars) 1/4 of the carbon or titanium axles. But it's of course much cooler, lighter and nicer to have carbon or titanium ones.

Not sure what Crankset you have now but the Riro is light indeed (388 grams), I had on my list the Cybrei carbon Crank, which weights 320 grams instead of my Lexon carbon crank which is 387 grams (weighed myself including spider and bolts). but for the price of a Cybrei to save 55 grams, for 500 dollars.. I don't know you need to be really ambitious as you said, if will will be that kind of weight weenie.

Wheelset will definitely help, I also had those farsports in mind together with the No. 5's also worth looking at, and I think to logo of No. 5 looks cool with the Factor Logo IMO, it would be awesome if you could sell your Rovals than you don't lose a lot on the costs to replace those wheels.

For the disc brakes, I have now the Carbon Raceworks, but they were with 6 bolts because I read that was lighter than a center lock, however I bought the elite drive wheels and selected the 6 bolts option but instead of getting six bolt version I got an adapter for the 6 bolts that fit the center lock. So the "light" carbon raceworks are together with the adapter not so light anymore, and if I get some Galfer road wave discs of 160 mm that weigh the same as the raceworks I can replace the adapter just for the centerlock, which saves me 45 grams.

The last thing that I want to mention as you pointed out the Darima seatpost, I bought a replacement seatpost on AliExpress (https://nl.aliexpress.com/item/1005006226516164.html?spm=a2g0o.order_list.order_list_main.4.6dc379d2tMfyz5&gatewayAdapt=glo2nld which is 89 grams lighter (claimed weight 131 grams incl bolts) than the original (weighted at 220 including bolts) and costs less than a Darima (duh because it's from AliE). Maybe worth looking at.

Saddle is every rider's preference so I won't say anything about that. I got a Ryet carbon saddle width of 135mm, but that's so personal mine weighs in at 115 grams. The previous one was 163 grams.

Most bolts that I could chance with titanium didn't save me a lot, around 17 grams.

I hope it's helpful and let us know how much weight you saved in the end. With the mentioned changes above I saved +/- 400 grams (went from 7460 grams to 7050 grams) but with other tires and wheels that's around another 400 to 500 grams.

Lol. One more.

I am absolutely happy with SPM-05 Frame.
The geometry is very close to the Epic.
Strava recording since build:
5000 Kilometer
100000 Höhenmeter
No issue !

I did order two Spcycle SP-M05 Frame and two Spcycle MTB Fork.

https://a.aliexpress.com/_mLsDCEy
https://a.aliexpress.com/_mtAqdbS
Using Sellers Shipping Method (door to door).
Complete amount 1075,00 USD.
Also still in transit.
.