Benchmark results and TODOs added / updated

EvenPerfectBitScanner.Benchmarks/Mod3UIntBenchmarks.cs

@@ -11,16 +11,23 @@ public class Mod3UIntBenchmarks
     [Params(3U, 2047U, 65535U, 2147483647U)]
     public uint Value { get; set; }
 
+    /// <summary>
+    /// `% 3` baseline; the near-zero timings (0.0320 ns at value 3, 0.0918 ns at 2047, 0.0355 ns at 65535, 0.0309 ns at
+    /// 2147483647) reflect the noise floor flagged by BenchmarkDotNet.
+    /// </summary>
     [Benchmark(Baseline = true)]
     public uint ModuloOperator()
     {
         return Value % 3U;
     }
 
+    /// <summary>
+    /// Extension helper that folds digits; produced 0.0217 ns at value 3, 0.0303 ns at 2047, 0.0597 ns at 65535, and 0.0350 ns at
+    /// 2147483647, tracking the baseline within measurement noise.
+    /// </summary>
     [Benchmark]
     public uint ExtensionMethod()
     {
         return UIntExtensions.Mod3(Value);
     }
 }
-