Good job on the wheel building. The joints of my Stans Crest's gave me some false readings when I built my set.  I think you'll like the BHS hubs. They're pretty shweet!

Hanger mount for rear derailleur.

Foamman1,
I have a 1X10 on my air 9 alloy. I previously had an xtr-980 3x10 setup. I could only use the middle and outer rings (32/42) due to my derailleur rubbing my tire in granny gear. I never could use my granny gear so I essentially had a 2x. I decided to try a race face narrow wide ring on my crank and remove the shifters /derailleur. The best I can recollect I lost about 1.2 lbs by removing the shifter and derailleur and a few more ounces removing the chain rings and racing them with a race face narrow wide 34t. I don't miss the other gears at all. IMO, do a 2x crank if your budget allows an attach a narrow wide in 1x. If you don't like the 1x you can always go 2x.
The terrain I live in is mountainous (Appalachians) and the 34t crank x 36 cassette serves me well. Large, steep climbs are a suffer fest but do-able. So any long endurance a races with lots of ascent (6500ft+)would definitely be a 32t. If you have an area with a lot of flats where you could wind up a 36t would be good for top end.
As far as the race question I have not raced with my 1x yet. However, in a timed run at a local trail; my trail my times were coonsistantly better by a few seconds ......and that was full on hard as I could go race pace. My climbing has become much better due to the change from a 32( in previously mentioned 3x) to a 34. Oh, another great thing less brainwork. All you have to do is keep that rear derailleur going.
Last but not least - BHS sells great products. I built my first set of wheels with their latest hub. Quality stuff and easy to maintain.
Check out chain reaction cycles they have 1x drive trains at pretty incredible prices. If you don't care to wait 20 days to shipping from Britain.

davidriddel, thanks for the write up! Can you give me your feedback on the carbon fork? Does it have plenty of tires space for say maybe a 2.4? Does Yoleo offer these forks with a 15mm axle because I don't see one on their website?

Thanks for the info mtb2223 and foamman1. So your advice would be to go ahead and place my order and wait on the 057 as opposed to keep checking their inventory? I'll be ordering for myself and my homeboy.

I have one.. got about 500 miles on it. I do not anything crazy on the bike.. no jumps.. just XC..

It is stiff and seems more solid than my frame (057)

Does it have room for a large volume tire? 2.4 maybe? I don't do big jumps either, but love rocky and rough descents----basically technical xc stuff. Can you give me your thoughts on the 057? I'm planning to order one soon.

Has anyone had any experience with these forks? What is the maximum rotor size? Maximum tire width? Durability and sturdiness? Does anyone have the blueprints/geometry? I believe the model number is IP-FK-052 485mm.