Patched GetCustomMode. Should do the trick now.

csharp/src/patch/PatchExperienceModeManager.cs

@@ -29,9 +29,75 @@ static bool Prefix(ExperienceModeManager __instance, bool __result) {
     class PatchExperienceModeManagerGetCustomMode {
 
         // - returns a boolean that controls if original is executed (true) or not (false)
-        static bool Prefix(ExperienceModeManager __instance, __) {
+        static bool Prefix(ExperienceModeManager __instance, CustomExperienceMode __result) {
+            ExperienceModeType _m = __instance.GetCurrentExperienceModeType();
+            if (_m == ExperienceModeType.ChallengeHunted
+                || _m == ExperienceModeType.ChallengeHuntedPart2
+                || _m == ExperienceModeType.ChallengeNomad
+                || _m == ExperienceModeType.ChallengeRescue
+                || _m == ExperienceModeType.ChallengeWhiteout) {
 
+                CustomExperienceMode res = new CustomExperienceMode();
+                res.m_AuroraFrequency = DifficultySettings.m_AuroraFrequency;
+                res.m_BaseWorldDifficulty = DifficultySettings.m_BaseWorldDifficulty;
+                res.m_ScentIncreaseFromMeatBlood = DifficultySettings.m_ScentIncreaseFromMeatBlood;
+                res.m_PlantSpawnFrequency = DifficultySettings.m_PlantSpawnFrequency;
+                res.m_WildlifeDetectionRange = DifficultySettings.m_WildlifeDetectionRange;
+                res.m_WildlifeSpawnFrequency = DifficultySettings.m_WildlifeSpawnFrequency;
+                res.m_WindVariability = DifficultySettings.m_WindVariability;
+                res.m_WolfFleeChance = DifficultySettings.m_WolfFleeChance;
+                res.m_WildlifeNotAttackUnprovoked = DifficultySettings.m_WildlifeNotAttackUnprovoked;
+                res.m_EnableBrokenRibs = DifficultySettings.m_EnableBrokenRibs;
+                res.m_CabinFeverEnabled = DifficultySettings.m_CabinFeverEnabled;
+                res.m_RiflesInWorld = DifficultySettings.m_RiflesInWorld;
+                res.m_EnableDysentery = DifficultySettings.m_EnableDysentery;
+                res.m_EnableFoodPoisoning = DifficultySettings.m_EnableFoodPoisoning;
+                res.m_AdjustFreezingDueToNearbyFire = DifficultySettings.m_AdjustFreezingDueToNearbyFire;
+                res.m_FrosbiteRisk = DifficultySettings.m_FrosbiteRisk;
+                res.m_ParasitesEnabled = DifficultySettings.m_ParasitesEnabled;
+                res.m_AllowInteriorStartingSpawn = DifficultySettings.m_AllowInteriorStartingSpawn;
+                res.m_StartWeather = DifficultySettings.m_StartWeather;
+                res.m_StartTimeOfDay = DifficultySettings.m_StartTimeOfDay;
+                res.m_SurvivorVoiceOver = DifficultySettings.m_SurvivorVoiceOver;
+                res.m_LimitedRest = DifficultySettings.m_LimitedRest;
+                res.m_InterruptIfFreezingWhileSleeping = DifficultySettings.m_InterruptIfFreezingWhileSleeping;
+                res.m_WildlifeInterruptRest = DifficultySettings.m_WildlifeInterruptRest;
+                res.m_BearSpawnChance = DifficultySettings.m_BearSpawnChance;
+                res.m_WolfSpawnChance = DifficultySettings.m_WolfSpawnChance;
+                res.m_MooseSpawnChance = DifficultySettings.m_MooseSpawnChance;
+                res.m_DeerSpawnChance = DifficultySettings.m_DeerSpawnChance;
+                res.m_RabbitSpawnChance = DifficultySettings.m_RabbitSpawnChance;
+                res.m_NoPredatorsFirstDay = DifficultySettings.m_NoPredatorsFirstDay;
+                res.m_EnableSprains = DifficultySettings.m_EnableSprains;
+                res.m_StartingGear = DifficultySettings.m_StartingGear;
+                res.m_StruggleDamageEventSeverity = DifficultySettings.m_StruggleDamageEventSeverity;
+                res.m_UseMinAirTempValue = DifficultySettings.m_UseMinAirTempValue;
+                res.m_DayNightLengthMultiplier = DifficultySettings.m_DayNightLengthMultiplier;
+                res.m_WeatherChangeFrequency = DifficultySettings.m_WeatherChangeFrequency;
+                res.m_BlizzardFrequency = DifficultySettings.m_BlizzardFrequency;
+                res.m_GradualTempReductionRate = DifficultySettings.m_GradualTempReductionRate;
+                res.m_CalorieBurnRate = DifficultySettings.m_CalorieBurnRate;
+                res.m_ThirstIncrease = DifficultySettings.m_ThirstIncrease;
+                res.m_FatigueIncrease = DifficultySettings.m_FatigueIncrease;
+                res.m_FreezingIncrease = DifficultySettings.m_FreezingIncrease;
+                res.m_ConditionRecoveryAwake = DifficultySettings.m_ConditionRecoveryAwake;
+                res.m_ConditionRecoveryRest = DifficultySettings.m_ConditionRecoveryRest;
+                res.m_HoursWarmthToCureHypothermia = DifficultySettings.m_HoursWarmthToCureHypothermia;
+                res.m_ItemDecayRate = DifficultySettings.m_ItemDecayRate;
+                res.m_ItemSpawnChance = DifficultySettings.m_ItemSpawnChance;
+                res.m_EmptyContainerChance = DifficultySettings.m_EmptyContainerChance;
+                res.m_StickBranchStoneSpawnFrequency = DifficultySettings.m_StickBranchStoneSpawnFrequency;
+                res.m_ReduceMaxItemsContainers = DifficultySettings.m_ReduceMaxItemsContainers;
+                res.m_StrugglePlayerStrengthBonus = DifficultySettings.m_StrugglePlayerStrengthBonus;
+                res.m_StruggleDamageReceivedBonus = DifficultySettings.m_StruggleDamageReceivedBonus;
+                res.m_StruggleClothingDamageBonus = DifficultySettings.m_StruggleClothingDamageBonus;
+                res.m_FishSpawnChance = DifficultySettings.m_FishSpawnChance;
+                res.m_WildlifeSmellRange = DifficultySettings.m_WildlifeSmellRange;
+                res.m_ReduceWildlifePopOverTime = DifficultySettings.m_ReduceWildlifePopOverTime;
 
+                __result = res;
+                return false;
+            }
             return true;
         }
     }