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
if (need_activate_chain) {
        BlockValidationState state;
        if (!ActivateBestChain(state, chainparams, a_recent_block)) {
            LogPrint(BCLog::NET, "failed to activate chain (%s)\n", state.ToString());
        }
    }
    LOCK(cs_main);
    const CBlockIndex* pindex = LookupBlockIndex(inv.hash);
    if (pindex) {
        send = BlockRequestAllowed(pindex, consensusParams);
        if (!send) {
            LogPrint(BCLog::NET, "%s: ignoring request from peer=%i for old block that isn't in the main chain\n", __func__, pfrom.GetId());
        }
    }
    const CNetMsgMaker msgMaker(pfrom.GetCommonVersion());
    
    if (send &&
        connman.OutboundTargetReached(true) &&
        (((pindexBestHeader != nullptr) && (pindexBestHeader->GetBlockTime() - pindex->GetBlockTime() > HISTORICAL_BLOCK_AGE)) || inv.IsMsgFilteredBlk()) &&
        !pfrom.HasPermission(PF_DOWNLOAD) 
    ) {
        LogPrint(BCLog::NET, "historical block serving limit reached, disconnect peer=%d\n", pfrom.GetId());
        
        pfrom.fDisconnect = true;
        send = false;
    }
    
    if (send && !pfrom.HasPermission(PF_NOBAN) && (
            (((pfrom.GetLocalServices() & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((pfrom.GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) && (::ChainActive().Tip()->nHeight - pindex->nHeight > (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2 ) )
       )) {