There are some potential feefilter cleanups mentioned and motivated in comment https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-805808485 . If you address the locking one, please be careful and make sure that `round()` is only called under a lock. See https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-807992199

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CChainState* m_active_chainstate GUARDED_BY(::cs_main) {nullptr};
    
    
    bool m_snapshot_validated{false};
    
    [[nodiscard]] bool PopulateAndValidateSnapshot(
        CChainState& snapshot_chainstate,
        CAutoFile& coins_file,
        const SnapshotMetadata& metadata);
    
    friend CChainState& ChainstateActive();
    friend CChain& ChainActive();
public:
    std::thread m_load_block;
    
    
    BlockManager m_blockman GUARDED_BY(::cs_main);
    
    
    int64_t m_total_coinstip_cache{0};