What do you mean by "flaws"? I'm sure it works as written, but the design drives the network topology towards highly centralized nodes.
In other words; The "Green Squares" are on centralized servers and not on a broad distributed system, which is why I object to people that refer to DAG as some kind of alternative to the blockchain when it simply doesn't work in that use-case (A highly distributed trustless consensus).
For example when you answer questions like this;
Pascal L:
Lets say there are 100k TPS...won't that require a really strong server?
Come-from-Beyond:
Yes, or 100 weak ones.
No it's not "or 100 weak ones". The answer is that DAG works better the more centralized it is. That's the way it's designed. It doesn't work equivalently well between 1 "really strong [node]" or "100 weak ones".
On the flipside, Bitcoin's blocks, through POW and the block size limit, allow all transactions to be transferred to literally anyone that wants to run a full node.
It's this rate limitation over time (made possible by POW on discrete limited capacity blocks) which allows this synchronization to happen, which is explicitly destroyed in the DAG protocol.That doesn't mean DAG is "flawed", it just means that it doesn't work as a method to come to decentralized trustless consensus. That's why DAG/IOTA should be separated from the words "Distributed" and "Decentralized" with several paragraphs of clarification.