I hadn't heard that Raptor 2 was a complete redesign as a results of flaws discovered (I hadn't heard anything at all about why they made Raptor 2). Do you have a link where I can read more about this?
From what I observed (reading the normal Reddit fluff, listening to NSF banter, and Tim Dodd the EA's interview with Musk) the issue with Raptor was being able to produce it reliably and rapidly. In the EA interview with Elon you can see how much less plumbing and paraphernalia there is on V2. I think both versions "worked" (they have been running lots of full duration tests at McGregor) for quite a while. One of Elon's many insightful sayings is something like "The best designed part is no part"