diff --git a/pkg/agentdrain/cluster.go b/pkg/agentdrain/cluster.go
index 464e30839af..b8b11265f69 100644
--- a/pkg/agentdrain/cluster.go
+++ b/pkg/agentdrain/cluster.go
@@ -1,6 +1,10 @@
 package agentdrain
 
-import "github.com/github/gh-aw/pkg/logger"
+import (
+	"slices"
+
+	"github.com/github/gh-aw/pkg/logger"
+)
 
 var clusterLog = logger.New("agentdrain:cluster")
 
@@ -21,16 +25,14 @@ func newClusterStore() *clusterStore {
 func (s *clusterStore) add(template []string, stage string) *Cluster {
 	id := s.nextID
 	s.nextID++
-	tmpl := make([]string, len(template))
-	copy(tmpl, template)
 	c := &Cluster{
 		ID:       id,
-		Template: tmpl,
+		Template: slices.Clone(template),
 		Size:     1,
 		Stage:    stage,
 	}
 	s.clusters[id] = c
-	clusterLog.Printf("Created new cluster: id=%d, stage=%s, template_length=%d", id, stage, len(tmpl))
+	clusterLog.Printf("Created new cluster: id=%d, stage=%s, template_length=%d", id, stage, len(c.Template))
 	return c
 }
 
diff --git a/pkg/agentdrain/mask.go b/pkg/agentdrain/mask.go
index 3d3d031177e..e89ac6f1062 100644
--- a/pkg/agentdrain/mask.go
+++ b/pkg/agentdrain/mask.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/github/gh-aw/pkg/logger"
+	"github.com/github/gh-aw/pkg/sliceutil"
 )
 
 var maskLog = logger.New("agentdrain:mask")
@@ -63,12 +64,9 @@ func FlattenEvent(evt AgentEvent, excludeFields []string) string {
 		excluded[f] = true
 	}
 
-	keys := make([]string, 0, len(evt.Fields))
-	for k := range evt.Fields {
-		if !excluded[k] {
-			keys = append(keys, k)
-		}
-	}
+	keys := sliceutil.FilterMapKeys(evt.Fields, func(k string, _ string) bool {
+		return !excluded[k]
+	})
 	sort.Strings(keys)
 
 	parts := make([]string, 0, len(keys)+1)
diff --git a/pkg/agentdrain/persist.go b/pkg/agentdrain/persist.go
index 6422def0786..7c214d1709d 100644
--- a/pkg/agentdrain/persist.go
+++ b/pkg/agentdrain/persist.go
@@ -3,6 +3,7 @@ package agentdrain
 import (
 	"encoding/json"
 	"fmt"
+	"slices"
 
 	"github.com/github/gh-aw/pkg/logger"
 )
@@ -31,15 +32,14 @@ func (m *Miner) SaveJSON() ([]byte, error) {
 
 	persistLog.Printf("Saving miner state: clusters=%d", len(m.store.clusters))
 	snap := Snapshot{
-		Config: m.cfg,
-		NextID: m.store.nextID,
+		Config:   m.cfg,
+		NextID:   m.store.nextID,
+		Clusters: make([]SnapshotCluster, 0, len(m.store.clusters)),
 	}
 	for _, c := range m.store.clusters {
-		tmpl := make([]string, len(c.Template))
-		copy(tmpl, c.Template)
 		snap.Clusters = append(snap.Clusters, SnapshotCluster{
 			ID:       c.ID,
-			Template: tmpl,
+			Template: slices.Clone(c.Template),
 			Size:     c.Size,
 			Stage:    c.Stage,
 		})
@@ -71,11 +71,9 @@ func (m *Miner) LoadJSON(data []byte) error {
 	m.store.nextID = snap.NextID
 
 	for _, sc := range snap.Clusters {
-		tmpl := make([]string, len(sc.Template))
-		copy(tmpl, sc.Template)
 		c := &Cluster{
 			ID:       sc.ID,
-			Template: tmpl,
+			Template: slices.Clone(sc.Template),
 			Size:     sc.Size,
 			Stage:    sc.Stage,
 		}