A lot is getting lost in the noise, which is pretty important to consider as a customer.
1. Tavelo used what they had said was not their standard production method to cure the area around the BB shell on early orders. This should never happen. You should not be sending prototypes out to customers with the intent of making a running change early in production. This isn't like shipping software where later customers can update to the equivalent product; there is no way for most customers to fix these bikes. This speaks to the company and their decision-making, highlighting that they are shipping product before fully sorting production.
2. Blaming suppliers. This is a common one, and small brands usually do lack supplier leverage. I brought up my experience with my Guerciotti, which was generally a good bike outside of the BB issue. That small company shared the mold with Kestral and a few others and after a while the bike popped up in Flybike's catalog. While Carbonda never sold the exact same frame, one of the big differences you paid for vs. the Carbonda 696 was the use of Deda as the supplier for small parts vs. Neco or whoever. That matters, and it's also the job of the brand to select suppliers that can be depended on for quality and long-term support. Tavelo seems to have overlooked that, which is a pretty basic step.
3. The bike is highly integrated, but the design doesn't appear to have been qualified as an integrated system. This is highlighted by the issues with installing the D-shaped steerer plug, the immaturity of the seat post expander design, etc. Given that consumers can't go out and buy expanders since not all D shapes are the same, and the plastic covers and spacers are different, etc., this is a problem that's hard to resolve.
I don't think any of this is a result of poor workmanship at the factory. If anything, the Arow frame looks pretty clean regarding carbon construction in these videos and the visual design is sharp; management's decision-making and the immaturity of the design process, including the non-carbon components, are the problems here.