I have built a few bikes out of Chinese carbon frames since 2016, some for myself, some sold to fellow experienced riders that I've ridden together for years.
None of us are currently racing or training for races, only regular group rides 3-4 times a week, all of us have multiple road bikes that we have ridden for multiple years and well aware of the general limitations and quality of Chinese carbon frames purchased from the internet.
Internal cable routing are always PITA, especially in tight spaces between brake levers & stem, frame routing are usually easier since there is more room to work with.
My first Chinese carbon frame build was in 2016, frame purchased on eBay with rebates it cost me less than $300 for the frame/fork/seatpost/BB/headset to be shipped to me. However the seller shipped me the wrong size frame and after 2 months of back & forth on eBay, I was refunded the purchase price by eBay and get to keep the frame.
I completed the build with misc. parts I have avail. in my basement, complete bike probably less than $1200.
I put about 5-600 miles on it and determined that it was too small for my liking and sold it to a neighbor of mine who has been riding with me on this bike, he has put over 4k miles on the bike since 2017. The usual complaint is the seatpost slipping and front derailleur mount slipping... beyond that the shifting noise with hollow carbon frame, tends to amplify.
My second build was little easier, but cable routing through the handlebar still required much patience.
Completed bike was a very nice ride, comfortable yet efficient, I have put about 3k miles on it since 2018.
Good enough for under $2k build.
Similar problems as the previous bike, seatpost slippage & front derailleur slippage.
My third was the replacement frame from the original seller of the wrong sized frame that was shipped to me.
I received it late in the season 2018, so I have not spent much time working on it, but recently I've put more effort into finishing it.
As before, cable routing through the handlebar still PITA even with much practice.
Also working on a Chinese TT carbon bike.. bought in 2018.. trying to decide whether to go 1x10 or double.