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Besu is different from a lot of the Hyperledger project in that it is beholden to a standard (Ethereum Mainnet compatibility) that it does not control. While it participates in co-ordination of that standard Besu does not have simple control over it like the other DLT projects do.
Because of this When working with public networks such as Mainnet there is a critical need to use the most current version of Besu, no matter what the semantic compatibility is. Not dealing with a breaking change is the same as dropping the service. Mainnet is fairly good about maintaining backwards compatibility, but there are other smaller changes such as P2P network protocol upgrades and RPC APIs that update at an infrequent cadence.
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