I have managed to get my own things into the menu by adding this to the UCLASS to a USceneComponent
UCLASS(ClassGroup = JacksCustom, editinlinenew, meta = (BlueprintSpawnableComponent))
both editinlinenew and BlueprintSpawnableComponent are key here.
Not only that but by adding this to a UPointLightComponent i am able to make a custom light and effect its values with code. Neat!
However unreal crashes when i try to add anything, so for example this code builds fine but when you try to add the component into a blueprint it will crash;
UCLASS(ClassGroup = Jacks, editinlinenew, hidecategories = (Object, LOD, Lighting, TextureStreaming), meta = (BlueprintSpawnableComponent))
class UMyCustomLightComponent : public UPointLightComponent
UPROPERTY(VisibleAnywhere, Category = "Power")
UMyCustomLightComponent::UMyCustomLightComponent(const class FPostConstructInitializeProperties& PCIP)
SphereCore = PCIP.CreateEditorOnlyDefaultSubobject<USphereComponent>(this, TEXT("SphereCore"));