diff --git a/core/src/layout_diagnostics.rs b/core/src/layout_diagnostics.rs
index 71894c3..6950aa1 100644
--- a/core/src/layout_diagnostics.rs
+++ b/core/src/layout_diagnostics.rs
@@ -23,100 +23,70 @@ use std::{
     time::Instant,
 };
 
-#[derive(Clone, Copy)]
-pub(crate) enum Counter {
-    Updates,
-    DrawRequests,
-    WidgetDraws,
-    RegionNodeDraws,
-    SizeReads,
-    HintHits,
-    HintMisses,
-    ReuseAttempts,
-    ReuseExact,
-    ReuseMoved,
-    ReuseDirty,
-    ReuseWrongParent,
-    ReuseRemapped,
-    ReuseOutside,
-    ReuseWrongLayer,
-    ReuseWrongNode,
-    QueuePops,
-    DepthReads,
-    LocalRedraws,
-    SizeChanges,
-    ReaderEdges,
-    PrimitiveWrites,
-    TextRenders,
-    TextShapeHits,
-    TextShapes,
-    TextBreaks,
-    GlyphPlacements,
-    OutsidePinnedLen,
-    OutsideRelBase,
-    OutsideRegion,
+/// Declares a counter or timer kind beside the name its report prints. Two
+/// lists in the same order was one list too many: a variant inserted without
+/// its label moving with it renames every total after it, and nothing says
+/// so.
+macro_rules! labelled {
+    ($(#[$meta:meta])* $vis:vis enum $Name:ident { $($variant:ident = $label:literal,)* }) => {
+        $(#[$meta])*
+        #[derive(Clone, Copy)]
+        $vis enum $Name { $($variant,)* }
+
+        impl $Name {
+            const COUNT: usize = [$($label,)*].len();
+            const NAMES: [&'static str; Self::COUNT] = [$($label,)*];
+        }
+    };
 }
 
-impl Counter {
-    const COUNT: usize = Self::OutsideRegion as usize + 1;
-
-    const NAMES: [&'static str; Self::COUNT] = [
-        "updates",
-        "draw requests",
-        "widget draws",
-        "region-node draws",
-        "draw-result size reads",
-        "hint hits",
-        "hint misses",
-        "reuse attempts",
-        "reuse exact",
-        "reuse moved",
-        "reuse: dirty",
-        "reuse: wrong parent",
-        "reuse remapped",
-        "reuse: outside what it holds for",
-        "reuse: another layer",
-        "reuse: region-node choice changed",
-        "redraw queue pops",
-        "depth reads",
-        "local redraws",
-        "size changes",
-        "reader edges",
-        "primitive writes",
-        "text renders",
-        "text shape hits",
-        "text shapes",
-        "text line breaks",
-        "glyph placements",
-        "reuse outside: the length it was pinned to",
-        "reuse outside: a rel base",
-        "reuse outside: a region length",
-    ];
+labelled! {
+    pub(crate) enum Counter {
+        Updates = "updates",
+        DrawRequests = "draw requests",
+        WidgetDraws = "widget draws",
+        RegionNodeDraws = "region-node draws",
+        SizeReads = "draw-result size reads",
+        HintHits = "hint hits",
+        HintMisses = "hint misses",
+        ReuseAttempts = "reuse attempts",
+        ReuseExact = "reuse exact",
+        ReuseMoved = "reuse moved",
+        ReuseDirty = "reuse: dirty",
+        ReuseUndrawn = "reuse: nothing drawn to keep",
+        ReuseWrongParent = "reuse: wrong parent",
+        ReuseRemapped = "reuse remapped",
+        ReuseOutside = "reuse: outside what it holds for",
+        ReuseWrongLayer = "reuse: another layer",
+        ReuseWrongNode = "reuse: region-node choice changed",
+        ReuseWrongMask = "reuse: a different inherited mask",
+        QueuePops = "redraw queue pops",
+        DepthReads = "depth reads",
+        LocalRedraws = "local redraws",
+        SizeChanges = "size changes",
+        ReaderEdges = "reader edges",
+        PrimitiveWrites = "primitive writes",
+        TextRenders = "text renders",
+        TextShapeHits = "text shape hits",
+        TextShapes = "text shapes",
+        TextBreaks = "text line breaks",
+        GlyphPlacements = "glyph placements",
+        OutsidePinnedLen = "reuse outside: the length it was pinned to",
+        OutsideRelBase = "reuse outside: a rel base",
+        OutsideRegion = "reuse outside: a region length",
+    }
 }
 
-#[derive(Clone, Copy)]
-pub(crate) enum TimerKind {
-    Update,
-    FullLayout,
-    IncrementalLayout,
-    TextRender,
-    TextShape,
-    TextBreak,
-    GlyphPlacement,
-}
-
-impl TimerKind {
-    const COUNT: usize = Self::GlyphPlacement as usize + 1;
-
-    const NAMES: [&'static str; Self::COUNT] = [
-        "update total",
-        "full layout",
-        "incremental layout",
-        "text render",
-        "text shape",
-        "text line break",
-        "glyph placement",
-    ];
+labelled! {
+    pub(crate) enum TimerKind {
+        Update = "update total",
+        FullLayout = "full layout",
+        IncrementalLayout = "incremental layout",
+        TextRender = "text render",
+        TextShape = "text shape",
+        TextBreak = "text line break",
+        GlyphPlacement = "glyph placement",
+    }
 }
 
 #[derive(Clone)]
@@ -251,6 +221,8 @@ pub enum ReuseOutcome {
     Dirty,
     WrongParent,
     WrongLayer,
+    WrongMask,
+    WrongNode,
     Remapped,
     Outside,
     Undrawn,
diff --git a/core/src/ui/render_state.rs b/core/src/ui/render_state.rs
index c235836..bf57bf9 100644
--- a/core/src/ui/render_state.rs
+++ b/core/src/ui/render_state.rs
@@ -569,12 +569,18 @@ impl UiRenderState {
         };
         if !active.drawn {
             #[cfg(feature = "layout-diagnostics")]
-            diag::reuse(id, ReuseOutcome::Undrawn);
+            {
+                diag::bump(Counter::ReuseUndrawn);
+                diag::reuse(id, ReuseOutcome::Undrawn);
+            }
             return false;
         }
         if active.is_region_node() != info.region_node {
             #[cfg(feature = "layout-diagnostics")]
-            diag::bump(Counter::ReuseWrongNode);
+            {
+                diag::bump(Counter::ReuseWrongNode);
+                diag::reuse(id, ReuseOutcome::WrongNode);
+            }
             return false;
         }
         // Drawn on another layer: the drawing sits in that layer's list and
@@ -590,7 +596,15 @@ impl UiRenderState {
             }
             return false;
         }
+        // Its primitives name the mask it inherited, and a masking parent
+        // that redrew pushed another: keeping them would clip them by one
+        // nothing updates again.
         if active.parent_mask != info.mask {
+            #[cfg(feature = "layout-diagnostics")]
+            {
+                diag::bump(Counter::ReuseWrongMask);
+                diag::reuse(id, ReuseOutcome::WrongMask);
+            }
             return false;
         }
         // Drawn somewhere else in the tree: its box is in coordinates it no