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
return;
    }
    if (msg_type == NetMsgType::GETCFHEADERS) {
        ProcessGetCFHeaders(pfrom, vRecv, m_chainparams, m_connman);
        return;
    }
    if (msg_type == NetMsgType::GETCFCHECKPT) {
        ProcessGetCFCheckPt(pfrom, vRecv, m_chainparams, m_connman);
        return;
    }
    if (msg_type == NetMsgType::NOTFOUND) {
        
        LOCK(cs_main);
        CNodeState *state = State(pfrom.GetId());
        std::vector<CInv> vInv;
        vRecv >> vInv;
        if (vInv.size() <= MAX_PEER_TX_IN_FLIGHT + MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
            for (CInv &inv : vInv) {
                if (inv.IsGenTxMsg()) {
                    
                    
                    auto in_flight_it = state->m_tx_download.m_tx_in_flight.find(inv.hash);
                    if (in_flight_it == state->m_tx_download.m_tx_in_flight.end()) {
                        
                        
                        continue;
                    }
                    state->m_tx_download.m_tx_in_flight.erase(in_flight_it);
                    state->m_tx_download.m_tx_announced.erase(inv.hash);
                }