Idk if this still works, but this was a patch to add one of the madVR debander checks to neo_f3kdb, which this renames to mad_neo_f3kdb for testing. Make sure to disable CPU optimizations, since it's only added to the C++ code.

mad_neo_f3kdb.patch

diff --git a/src/flash3kyuu_deband_impl_c.cpp b/src/flash3kyuu_deband_impl_c.cpp
index f1e800b..31cd792 100644
--- a/src/flash3kyuu_deband_impl_c.cpp
+++ b/src/flash3kyuu_deband_impl_c.cpp
@@ -167,6 +167,14 @@ static __forceinline void __cdecl process_plane_plainc_mode12_high(const process
                     int diff4 = ref_4_up - src_px_up;
                     use_org_px_as_base = is_above_threshold(threshold, diff1, diff2, diff3, diff4);
                 }
+
+		int ref_pixel_sum = abs(ref_1_up - src_px_up);
+		ref_pixel_sum += abs(ref_2_up - src_px_up);
+		ref_pixel_sum += abs(ref_3_up - src_px_up);
+		ref_pixel_sum += abs(ref_4_up - src_px_up);
+
+		use_org_px_as_base = is_above_threshold(threshold * 3.25, ref_pixel_sum) + use_org_px_as_base;
+
                 new_pixel = use_org_px_as_base ? src_px_up : avg;
             }
 
diff --git a/src/neo_f3kdb.hpp b/src/neo_f3kdb.hpp
index 99207f9..097270e 100644
--- a/src/neo_f3kdb.hpp
+++ b/src/neo_f3kdb.hpp
@@ -11,8 +11,8 @@
 #include "f3kdb.hpp"
 
 namespace Plugin {
-  const char* Identifier = "in.7086.neo_f3kdb";
-  const char* Namespace = "neo_f3kdb";
+  const char* Identifier = "in.7086.mad_neo_f3kdb";
+  const char* Namespace = "mad_neo_f3kdb";
   const char* Description = "Neo F3KDB Deband Filter " PLUGIN_VERSION;
 }