diff --git a/common_libs/tests/measure_strafe_heat_display.nim b/common_libs/tests/measure_strafe_heat_display.nim
index 81fb4b6..6e68224 100644
--- a/common_libs/tests/measure_strafe_heat_display.nim
+++ b/common_libs/tests/measure_strafe_heat_display.nim
@@ -91,6 +91,7 @@ proc main() =
     svgTicks     = 0    ## ticks whose overlay was rendered and inspected
     svgBad       = 0    ## the chosen tile's heat NUMBER is not in the SVG
     svgNoPlate   = 0    ## the chosen tile's dark value plate is not in the SVG
+    svgNoRamp    = 0    ## the chosen tile's ramp border is not in the SVG
 
   for tick, ws in states:
     # The GUI half: render the overlay for the first `DrawWindow` ticks, with
@@ -99,8 +100,9 @@ proc main() =
     # Drawing is read-only, so the pick sequence stays byte-identical; the SVG
     # buffer is cleared every tick exactly as the framework does.
     m.debugGraphics = tick < DrawWindow
+    let gridOn = (tick mod 2 == 0)
     if m.debugGraphics:
-      StrafeHeatGrid = (tick mod 2 == 0)
+      StrafeHeatGrid = gridOn
       clearGraphics()
 
     discard m.computeMove(ws)
@@ -111,9 +113,16 @@ proc main() =
       clearGraphics()
       if m.targetValid and svg.len > 0:
         inc svgTicks
-        # The number printed ON the chosen tile, as the SVG sees it.
-        if not svg.contains(fmt">{m.targetPathHeat:.1f}</text>"): inc svgBad
+        # The chosen tile's ramp-coloured thick border + its dark value plate
+        # (both unique to the chosen-tile block, drawn whether or not the heat
+        # grid is on), and - with the grid ON only the chosen tile is labelled,
+        # so the number in the SVG is provably the chosen tile's -
+        # the chosen tile's heat NUMBER, as the SVG sees it.
+        if not svg.contains("stroke-width=\"3.5\""): inc svgNoRamp
+        if not svg.contains("stroke=\"" & heatRamp(m.targetPathHeat).toHex & "\""):
+          inc svgNoRamp
         if not svg.contains("fill=\"#000000\""): inc svgNoPlate
+        if gridOn and not svg.contains(fmt">{m.targetPathHeat:.1f}</text>"): inc svgBad
 
     if not m.targetValid: continue
     inc targetTicks
@@ -161,8 +170,10 @@ proc main() =
         fmt"({under} under / {over} over, {labelBad} bad)", labelBad == 0
   check fmt"`strafeHeatText` carries the displayed number ({textBad} bad)",
         textBad == 0
-  check fmt"the chosen tile's heat NUMBER is rendered on the tile, grid ON " &
-        fmt"and OFF ({svgTicks} rendered ticks, {svgBad} missing)", svgBad == 0
+  check fmt"the chosen tile's heat NUMBER is rendered on the tile with the " &
+        fmt"heat grid ON ({svgTicks} rendered ticks, {svgBad} missing)", svgBad == 0
+  check fmt"the chosen tile's ramp border is rendered ({svgNoRamp} missing)",
+        svgNoRamp == 0
   check fmt"the chosen tile's value plate is rendered ({svgNoPlate} missing)",
         svgNoPlate == 0
   check "the stream contains picks to check", picks > 0