Why are certain features disabled for DamageType subclasses?

Development Programming & Scripting
1

I am trying to create my custom DamageType base Blueprint to add a few utility functions that I could need for all the damage types in my game. So I created a Blueprint called MyDamageType that inherits directly from DamageType. The idea is that all further damage types inherit from it.

However, it seems that certain features are not available for custom damage type Blueprints:

  1. I cannot create any Macros in it.
  2. Local variables in any function seem to be automatically declared as constants. When I try to set one, the compiler throws me the error Cannot write to const.

I can’t see or find any reasons for this. Where do these limitations come from and is there a way around them?

I am using UnrealEngine 4.2.

2

I’m using 4.4.3. It doesnt seem like I can do anything with the DamageType blueprints.
From the EventAnyDamage node, off the DamageType node I did GetClass → GetDisplayName → switch on String. If that class is say, DefaultDamage_C, I do a GetClass, select that damage type, and then cast to that class, but I cant get my custom variables from it. And they dont even have a graph editor, so I’m not sure how I’m supposed to use them.

It looks like I’m going to have to edit the actor class ApplyDamage , and add custom damage over time type inputs. I was trying to stick to Blueprints.