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 (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && tx.GetWitnessHash() != tx.GetHash()) {
                    recentRejects->insert(tx.GetHash());
                }
                if (RecursiveDynamicUsage(*ptx) < 100000) {
                    AddToCompactExtraTransactions(ptx);
                }
            }
            if (pfrom.HasPermission(PF_FORCERELAY)) {
                
                
                
                
                if (!m_mempool.exists(tx.GetHash())) {
                    LogPrintf("Not relaying non-mempool transaction %s from forcerelay peer=%d\n", tx.GetHash().ToString(), pfrom.GetId());
                } else {
                    LogPrintf("Force relaying tx %s from peer=%d\n", tx.GetHash().ToString(), pfrom.GetId());
                    RelayTransaction(tx.GetHash(), tx.GetWitnessHash(), m_connman);
                }
            }
        }