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
m_connman.AddNewAddresses(vAddrOk, pfrom.addr, 2 * 60 * 60);
        if (vAddr.size() < 1000)
            pfrom.fGetAddr = false;
        if (pfrom.IsAddrFetchConn())
            pfrom.fDisconnect = true;
        return;
    }
    if (msg_type == NetMsgType::SENDHEADERS) {
        LOCK(cs_main);
        State(pfrom.GetId())->fPreferHeaders = true;
        return;
    }
    if (msg_type == NetMsgType::SENDCMPCT) {
        bool fAnnounceUsingCMPCTBLOCK = false;
        uint64_t nCMPCTBLOCKVersion = 0;
        vRecv >> fAnnounceUsingCMPCTBLOCK >> nCMPCTBLOCKVersion;
        if (nCMPCTBLOCKVersion == 1 || ((pfrom.GetLocalServices() & NODE_WITNESS) && nCMPCTBLOCKVersion == 2)) {
            LOCK(cs_main);
            
            if (!State(pfrom.GetId())->fProvidesHeaderAndIDs) {
                State(pfrom.GetId())->fProvidesHeaderAndIDs = true;
                State(pfrom.GetId())->fWantsCmpctWitness = nCMPCTBLOCKVersion == 2;
            }
            if (State(pfrom.GetId())->fWantsCmpctWitness == (nCMPCTBLOCKVersion == 2)) 
                State(pfrom.GetId())->fPreferHeaderAndIDs = fAnnounceUsingCMPCTBLOCK;
            if (!State(pfrom.GetId())->fSupportsDesiredCmpctVersion) {
                if (pfrom.GetLocalServices() & NODE_WITNESS)
                    State(pfrom.GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 2);
                else
                    State(pfrom.GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 1);