I've yet to meet anyone with experience of these Engines and as others have mentioned, it will be in the field experince over a good sized user base that will ultimately determine the success or lack of for any Product.
There may still be a sizeable market for use of this catagory of engines in Drones that could be leveraged.
Regarding Sub-ing out stuff leading to quality drops:
Rotax has always subbed out its 912 Cylinder production
I think it would be very hard to find an Engine manufacturer that doesnt do something similar , Pistons for example are routinely sourced elsewhere.
The perception that Chinese = poor quality has a sound base, my experience is that China whilst perfectly happy to churn out garbage is also very capable of high quality production when it is demanded.