UseStateForUnknown doesn't work when /null/ -- is this important?

Terraform Providers Plugin Development
1

I’ve been struggling to understand why my provider is seemingly expecting state churn for some optional + computed attributes. Then I noticed the specific language of the UseStateForUnknown() PlanModifier:

copies the prior state value for an attribute into that attribute’s plan, if that state is non-null.

It’s not obvious to me why this PlanModifier only applies to non-null values.

Is there something… Important? …about the fact that it ignores null values in the state?

Options I’m considering:

  • cloning the UseStateForUnknown PlanModifier with the ability to enforce null values.
  • saving my computed + optional lists and sets as empty, rather than null

If I’m missing something important, I’d sure appreciate a nudge to keep me off the rocks.

Thanks!