My FM936 has this translucent effect.
Kind of blue, and some transparent area.
Except some special sheets around the BB and pivots, it is a rather dull UD all the way.
So it makes a subtle effect you can only notice really on a bright sunny day.

I didn't know they had to sand it down first.

im in the market for 2x oval chainrings but so far the only set i can find in china(where i live) within my budget is the kcnc k5 blade 2

Wow. Not sure we can call these chainrings anymore... chainrectangles ?

Is the sensor loss universal, or just some units, or some sensors? 

I still feel like all of the options are crap.  Garmin 'just works' but maps, navigation and rerouting are all crap, and UX is prehistoric.  Wahoo Bolt V2 is laggy, they still haven't fixed their underreporting of power and work done (kJ) on anything other than Favero on any of their products & deny the issue exists, battery drain is insane when stopped or GPS is lost, no sleep mode or screen sleep mode, screen visibility worst in class. Karoo 2 - bad battery life and bugs galore - including by the sound of it a game breaking one with sensor loss.

It looses the powermeters on all my bikes, a p2m-road, sigeyi-mtb and quarq-gravel.
But it doesn't loose my heart rate either magene or a whoop.
Shifting sensors stay as well.

They made an update recently, limiting Ant+ sensors to 15, but that didn't help at all.
They told me on their support to change the priority of sensors depending the bike I ride    That didn't help either.
What is stupid, is when you get to the sensor page, it finds it back instantly.
Would it be possible a smart ass there would call the same function when re-starting a ride ?

I agree with you, all these devices look prehistoric, even the Karoo, compared to other apps we use daily.

But just to be clear, except this powermeter loss. If I train myself, I could think of passing by the sensor page before restarting the ride...
As well as the shortish 7h battery life(last longer if you turn your screen off when not riding).
I'm quite happy with it.

If it is 007Bike Store, you can trust them.
They just ship without the boxes.

Ok for geometry wise and tire clearance I’ve narrowed it to 2 choices:
1. Tantan GR029 or GR039
2. Carbonda CFR505

Anyone have experience with those 2? Which one has more compliance, and better for long distance comfort?

TanTan is quite so-so recently with their after sale support, if things go wrong.
And unfortunately the CFR505 is not sold by carbonda anymore.
You didn't like the CFR707?

I am 181cm and 81cm inseam.

What size do you think?  Background: road and a bit XC races

Very primitive calcs:

Top-tube thoughts:
  On my old cannondale flash 29er L-size: 62cm top-tube and ~10cm stem, so, total saddle-handlebar it is ~72cm
  FM936 can have the same 72cm on M (61cm) + 11cm stem or L + 8cm stem

Reach thoughts:
  Cannondale has 42.5cm reach, so looks like FM936 is very long M is 47.5cm and L is 50cm.
  Probably seat-tube angle eats about ~3cm (maybe I am wrong here) and if I remove seatback offset another 2cm, total 5 => 42.5cm or 45cm

Sounds like I have to go for M with long stem, but absolutely not sure, because I am non experienced technical XC racer

Thank you for any advice

--added--
Looks like I calculated tt wrong and fixed it, but still not sure which is better

I'm 178cm / 89cm and ride an M with a 65mm stem.
I think a L would have been good too, so probably good for your longer torso, and more in the spirit of the bike.

... 250-350W Gravel eBikes...

Are you counting bikes in watts ? 

...Quesion, is the GF-01 my best option? Does it work with standard Sram cx1 groupset?...

Velobuild has good reviews, but since you ask my opinion 
Personally I prefer to work with Carbonda for the great quality and service and after sale.

A new SRAM crank will be DUB, and will be compatible with any BB386-DUB BB.
WMFG are great.

Since my current bike is QR, I'd need new wheel. Since I'm both on road and in forest, I need 2 sets Plan is 1 set with communting/bikepack tires. Somethink like 32mm Continental 4seasons, and 1 set with graveltires (running 33mm challenge limos now, but guess that is more of a cross tire).

Except if you want high performance on asphalt, maybe one wheelset is enough with either Continental Terra speed 38 or 40mm or even better Maxxis Rambler 40mm are both great polyvalent tires except on deep mud.

...What would be a cheap and ok wheelset for this frame?
Does it make sense not to go for 650 wheels? If im going to go on harsh terrain I would take MTB anyway (IP-256sl, 1x10)

700c wheels roll much better, even on rocks & roots.
Look for the WR series of rims at lightbicycle.com, 32mm wide external.
My preferred are the WR38 
If on budget, with bitex hubs, pilar aero spokes but with brass nipples.