1. Improved diagnostics logging stuck header downloader.
2. Bor mainnet snapshots now available by default (download size 360 Gb).
3. Fixed syncing problem for Ropsten, new Ropsten TTD (terminal total difficulty) by default.
4. Fixed local snapshot creation problem causing the error DumpBlocks: DumpTxs: BigChunks: body not found. Recovery requires some manual steps or resync.
5. Re-designed block proposing (mining) mechanism to use read-only MDBX transaction and in-memory buffer instead of read-write MDBX transaction, fixed block proposing.
6. Various fixes for POS transition and hive test failures (still work in progress).
7. Updated skip analysis thresholds for Ethereum mainnet, Ropsten, BSC, and Bor mainnet.
8. Removed --syncmode command line flag, because it collided from the same flag of go-ethereum, but meant different thing. Introduced --snapshots flag instead.
9. Fixed tracing method in RPC methods for transactions containing BLOCKHASH opcode - it worked incorrectly for blocks within snapshots.