The "Creation Flags" enum on the Create Dynamic Material Instance node: What does it do?

[RainyGames]

That’s it. There’s no documentation on it, what does it do? What does None vs Transient mean?

[ilya.83]

^bump^ same question

[3dRaven]

transient, meaning it will not be saved or loaded. Properties tagged this way will be zero-filled at load time.

It’s the Kismet variant of the function.
The comment inside the code:

// In editor MIDs need to be created within a persistent object or else they will not be saved.
// If this MID is created at runtime or specifically marked as transient then put it in the transient package.