Turns out I corrected some of the delays too far the other way.

tetris/modes/marathon_a2.lua

@@ -35,9 +35,9 @@ function MarathonA2Game:new()
 end
 
 function MarathonA2Game:getARE()
-        if self.level < 700 then return 28
+        if self.level < 700 then return 27
-    elseif self.level < 800 then return 19
+    elseif self.level < 800 then return 18
-    else return 15 end
+    else return 14 end
 end
 
 function MarathonA2Game:getLineARE()
@@ -54,11 +54,11 @@ function MarathonA2Game:getDasLimit()
 end
 
 function MarathonA2Game:getLineClearDelay()
-        if self.level < 500 then return 41
+        if self.level < 500 then return 40
-    elseif self.level < 600 then return 26
+    elseif self.level < 600 then return 25
-    elseif self.level < 700 then return 17
+    elseif self.level < 700 then return 16
-    elseif self.level < 800 then return 13
+    elseif self.level < 800 then return 12
-    else return 7 end
+    else return 6 end
 end
 
 function MarathonA2Game:getLockDelay()

tetris/modes/survival_a2.lua

@@ -46,7 +46,7 @@ function SurvivalA2Game:getDasLimit()
 end
 
 function SurvivalA2Game:getLineClearDelay()
-	return self:getLineARE()
+	return self:getLineARE() - 2
 end
 
 function SurvivalA2Game:getLockDelay()