Yes, I spent too many hours looking for a Chinese frame. The only vendors advertising 29+ are Carbon Speed and another guy who sells at eBay and AliExpress. The latter vendor never directly answered the most critical Qs. CS never returned multiple contact attempts, a far cry from the days when Peter was there (someone posted he's long gone, hopefully to greener pastures). CS with Peter was A+, without it is nothing. Peter WAS Carbon Speed.
Re your Trek Stache 9.8: Circa 2017 I took one for a test ride, and I absolutely regret not buying that XL size 9.8, by yuge margin the best bike I ever rode. If there's a mountain bike equivalent to a BMW M3, that's it. (Yes, I've driven two M3's, an early 2k 911, and a 160+hp motorcycle). Absolute comfort, control, and performance. Price was in the low $4k range; at the time it was about $1k more than I wanted to spend. I wish I got it anyway. You seldom regret spending a little too much, and conversely, the aroma of inferior bargain soon fades.
Last week I bought a NOS/half price closeout Salsa Woodsmoke NX-1 27.5+, carbon frame, infinitely variable wheelbase, offset chain stay ala Stache (AFAIK Trek invented the offset chain stay). From what I've read our frames are very similar. WS @ Universal Cycles, add US tax + $200 for shipping, but the bike arrives almost ready to ride: fasten the front wheel, fasten pedals, fasten the seat, air in the tires, coarse fork adjustments, and ride. Assembly took only a little longer than unpacking.
For reader's info: WS frame accommodates everything from 27.5 x 3.25 to 29 x 3.00. I have and now install Bontrager XR2 29 x 2.6 on Carbon Speed 36mm rims/wheel set (purchased from Peter, absolutely perfect tire/rim width combination).
Just to compare, I first rode my stock WS last night with stock alloy 27.5 x 3.00, and was surprised how much I liked it. Your 9.8 is full carbon throughout, a universe beyond a stock WS NX-1. But the NX-1 shifts surprisingly well, and the plush plus tires rollover rocks really well, super high sense of security, including so-called "edge traps" like driveway bumps; plus tires provide a safety margin for edge traps smaller width tires can't match.
Swapping my 29s onto the WS now; estimate half the weight of the stock WS wheels.
Between these two 11 speed derailleurs, which would you select?
Shimano Deore XT, low/moderate miles
SRAM NX-1, brand spanking new
IIRC 2 guys at the LBS said the Shimano is easier to service, but no idea how much weight this deservers in my choice.
I already have, and plan to mount on the WS pretty much full carbon build like your lovely 9.8, including crank, bars, etc.
Please comment if you can compare my carbon WS frame to your carbon Stache. Honestly, if, when I'm done, I still prefer the Stache, I'll just admit defeat and get either a used 9.8 or buy the carbon Stache frame, $1700, ouch! Again, should have just bought the bike 3 years ago!
Would you consider down-sizing to 29 x 2.6? Ever ridden 29 x 2.6? Describe your typical ride. Again, if there's a perfect single mountain bike from the factory, IMO the all-carbon 9.8 is it.