Carbonda told me it was 120mm linkage will be available this week

Is this true? Carbonda plans a linkage for FM909 to support 120mm travel suspension?
Any link you can share?

Thanks & regards,
Michael

My frame already had a hole at the BB

Same here

Does anyone have a diagram of how the headset goes together? Is the top bearing, then that half circle thing, then the top cap and washer? That leaves a hole…

First the top bearing, then that half circle thing, then the washer (if necessary and you have to cut the washer to keep the hole for the cables) and then the top cap.
If you use internal routing (through the headset) I recommend to use FSA ACR headset.
Why? The half circle thing is much better with rounded edges and the top cap has a sealing.

I'm sorry to ask again if you have answered this already, but what handlebar and spacers do you have that allow for internal routing?

Did you visit Carbonda website ever?
https://www.carbonda.com/mountain/full-suspension/130.html

Hmm, what are you doing to replace the short shock bolt?

Make a new one!
And of course starting a complaint at Carbonda, it seems that others have received a bolt which fits.

I have ordered a second hanger as a spare but it is impossible to screw in the rear axle.
The opening of the hanger is smaller than the thread in the hanger 
Seems Carbonda has some serious issues with their suppliers QC
I raised a complaint for this one, too.

Nice!
Do you know your chain line in the crankset and size of chainring?

That was indeed not an easy thing...
e13 is mentioning a 52mm chainline for boost frames with this crankset.
I bought the crankset "used" comming with a 34T chainring with -5mm offset.
The bottom bracket required a spacer of 2,5mm according manual at chainring side.
Using the 2,5mm spacer the spindle was too short, crankset only moved very hard.
So I did not use 2,5mm spacer as also e13 XCX manual mentioned not to use the spacer.
I am a fan of oval chainring therefore I have ordered a boost chainring 32T but the chainline did significantly degrade.
Finally the chainring supplier recommended a non boost chainring with -5mm offset which was much better in regards
to the chainline but the chainring was slightly touching the frame.
I remembered myself to the 2,5mm spacer for the bottom bracket and grinded one of them to 1mm.
Now there is space between frame and chainring of about 1mm.
This is best I could achieve, let´s see how it works in reality.

I am thinking about something like that:

https://noso.store/pl/p/Hybrydowa-oslona-ramy-powloka-absorbujaca/316?gclid=CjwKCAiA0KmPBhBqEiwAJqKK40-rTjPSufPxFgNhM6W0mD4Am2I7wDlkvWdwK2UlX0O63zoLbGrSlBoCc8UQAvD_BwE

Looks like being bullet proofed 

Some of the details of my build.  Shock pivot pin threads were kind of buggered up, so made a new Ti pin with some stainless bolts.  Also turned a custom 8mm to 1/2 bushing for shock mount out of TECAPEEK.  Accents in copper, plan was for "dolemite" to be in chrome, but that failed miserably so black for now.

Did you modify the shock pivot pin in length?
Mine is around 2mm too short. If I tighten the screw the bushing for shock mount will be clamped in a way that it can only move the rear shock with quite big force.

Thanks