AFAICT, as of commit a0a422c,  we have 2 different logics to evict outbound peers : lagging-chain (`ConsiderEviction`) and (`CheckForStaleTipAndEvictPeers`). The former to sanitize out lazy/buggy peers who have never sent us a valid header and are always staying behind our tip, the latter triggered in case of stale tip due to block variance to seek a better chain by rotating our outbound peers if we already reach an outbound limit (`EvictExtraOutboundPeers`).

Block-relay-only peers were introduced by #15719. Contrary to outbound full-relay peers who provided us at least a useful header, they're not protected by lagging-chain eviction.

We actually have a comment inside `ProcessHeadersMessage` indicating the contrary behavior. We should either document cleanly that block-relay-only aren't protected or effectively extend the scope of protection to them.

Hinted during #19724 review, see https://github.com/bitcoin/bitcoin/pull/19724#discussion_r475144532
: address(addrIn), m_is_inbound(is_inbound), m_is_manual_connection(is_manual)
    {
        fCurrentlyConnected = false;
        pindexBestKnownBlock = nullptr;
        hashLastUnknownBlock.SetNull();
        pindexLastCommonBlock = nullptr;
        pindexBestHeaderSent = nullptr;
        nUnconnectingHeaders = 0;
        fSyncStarted = false;
        nHeadersSyncTimeout = 0;
        nStallingSince = 0;
        nDownloadingSince = 0;
        nBlocksInFlight = 0;
        nBlocksInFlightValidHeaders = 0;
        fPreferredDownload = false;
        fPreferHeaders = false;
        fPreferHeaderAndIDs = false;
        fProvidesHeaderAndIDs = false;
        fHaveWitness = false;
        fWantsCmpctWitness = false;
        fSupportsDesiredCmpctVersion = false;
        m_chain_sync = { 0, nullptr, false, false };
        m_last_block_announcement = 0;
        m_recently_announced_invs.reset();
    }
};
limitedmap<uint256, std::chrono::microseconds> g_already_asked_for GUARDED_BY(cs_main)(MAX_INV_SZ);
static std::map<NodeId, CNodeState> mapNodeState GUARDED_BY(cs_main);
static CNodeState *State(NodeId pnode) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {