1228g, 40mm road wheels,  29 x 21 x 40mm asymmetrical clincher.

There might be some R&D costs that went into electronic group sets they are still trying to pay off, even if manufacturing should be cheaper than mechanical

That's wishful thinking unfortunately. These companies have been patent trolling for years, it's been the new rule of the game for many years. A friend used to be an intellectual property lawyer in London, representing the likes of Amazon. It is impossible to imagine how cunning these companies are at preventing competition. Amazon for example has patented so much shit related to conveyor belts that it's almost impossible to achieve their efficiency without tripping patents. Is it fair? Absolutely not.
SRAM and Shimano do essentially the same thing.
At these price levels, it's pure price gouging. Especially when you consider the price difference between OEM pricing and retail pricing, especially on Shimano.

There might be some R&D costs that went into electronic group sets they are still trying to pay off, even if manufacturing should be cheaper than mechanical

I build both TanTan GR29 and a Wind GT20 in the past with no issues, both bikes still working fine.
Built process was painless.

Here the GR29 thread:
https://chinertown.com/index.php/topic,3118.msg25125.html#msg25125

And here the GT20:
https://chinertown.com/index.php/topic,4030.msg42760.html#msg42760

The Second bike you linked, the CWind GT30 is interesting especially since it is using T47 BB which is a good choice and leaves all crank options open. There might be different manufacturers / Distributors selling this frame under a different name. CWind is nice since they include all parts such as Headset and through axles, while at TanTan/Seraph make sure to order them matching to your frame separately.

BR Chris

Maybe "binning" occurs where Western re-branders like PP, Planet X, Vitus, Ribble, Ritte, probably Enve, et al get the frames on the better side of the QC bell curve?

Sorry what? Panda Podium is just a retailer and the current Ritte and Enve are bike brands with unique products. I don't think anything is being binned differently between Tavelo products let alone between open molds and Ritte or Enve bikes.

Has anyone even confirmed that this Tavelo is an open mold that you can buy through a different brand like the Attack was?

While I could believe binning is done during initial production runs to get new bikes out for race teams, this doesnt make sense as a general practice because it assumes that the QC would be good enough to sort the frames at a per frame level and that the factories would be willing to incur that cost on an ongoing basis.

On the other hand, I think its more surprising that XDS and Pardus have not tried to go more international given their involvement in the chinese olympic team efforts. That said, if a company goes big into road racing, I would bet on Farsports.