It's unfortunately something I can't fix myself, since I'm no C# wizard, and the code I used for the healing of wounds like that comes from the Community Framework.

Got the same problem with body parts removal. The saddest part is that you can partially fix it with the mod named "Prosthetic No Missing Body Parts", but only for arms and legs. The heart still removes itself. I am a complete zero in terms of code, so just in case i leave my error message for you. It would be a bless if it could help somehow.



Exception ticking hediff (NanomachinesSon_Heart heart ticksSinceCreation=60000) for pawn Jesus. Removing hediff... Exception: System.InvalidCastException: Specified cast is not valid.
at CF.CommunityHealthUtility.RestorePartRecursiveInt (Verse.Pawn pawn, Verse.BodyPartRecord part, System.Boolean& alreadyWarned) [0x00024] in <2a1fe854cdf84ca7a92e4e13fe10f54c>:0
at CF.CommunityHealthUtility.RestorePartRecursiveInt (Verse.Pawn pawn, Verse.BodyPartRecord part) [0x00002] in <2a1fe854cdf84ca7a92e4e13fe10f54c>:0
at CF.CommunityHealthUtility.RestorePartInt (Verse.Pawn pawn, Verse.BodyPartRecord part) [0x0000e] in <2a1fe854cdf84ca7a92e4e13fe10f54c>:0
at CF.CommunityHealthUtility.TryHealRandomPermanentWoundFor (Verse.Pawn pawn, Verse.HediffWithComps cause, System.Collections.Generic.List`1[T] blacklist, System.Collections.Generic.List`1[T] whitelist, System.Collections.Generic.List`1[T] sideEffects, System.Boolean canHealDestroyed, CF.InjuryRegenListMode injuryMode) [0x0016c] in <2a1fe854cdf84ca7a92e4e13fe10f54c>:0
at CF.HediffComp_HealPermanentWoundsConfigurable.TryHealPermanentWound () [0x0003e] in <2a1fe854cdf84ca7a92e4e13fe10f54c>:0
at (wrapper dynamic-method) CF.HediffComp_HealPermanentWoundsConfigurable.CF.HediffComp_HealPermanentWoundsConfigurable.CompPostTick_Patch0(CF.HediffComp_HealPermanentWoundsConfigurable,single&)
at Verse.HediffWithComps.PostTick () [0x00024] in <464202b7bbde412f9e6a1b26080987a9>:0
at (wrapper dynamic-method) Verse.Pawn_HealthTracker.Verse.Pawn_HealthTracker.HealthTick_Patch2(Verse.Pawn_HealthTracker)
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
(wrapper dynamic-method) Verse.Pawn_HealthTracker:Verse.Pawn_HealthTracker.HealthTick_Patch2 (Verse.Pawn_HealthTracker)
(wrapper dynamic-method) Verse.Pawn:Verse.Pawn.Tick_Patch4 (Verse.Pawn)
(wrapper dynamic-method) Verse.TickList:Verse.TickList.Tick_Patch2 (Verse.TickList)
(wrapper dynamic-method) Verse.TickManager:Verse.TickManager.DoSingleTick_Patch2 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
(wrapper dynamic-method) Verse.Game:Verse.Game.UpdatePlay_Patch1 (Verse.Game)
Verse.Root_Play:Update ()

So i'd like to leave my solution to this problem in case someone else will face it in the future.
Try mod named "Medical System Expansion 2" https://steamcommunity.com/sharedfiles/filedetails/?id=2056706586. One of it's features - it kinda disables "removal" of body parts via implants, but not only for limbs. Hope it helps.

1.4 update dropped and I noticed the update says it won't try to regenerate replaced limbs. Fingers crossed!

I know its been a while but has anyone found a way of fixing this?