How do you populate existing entities with the default value for a newly added field? Let's say I have a content type, Article, with several fields. I already have hundreds of Article nodes created, but now I want to add a new field. After I set a default value for this field, how can I make it so that all existing Articles have this new field populated with this value? In other words, I don't want all my existing Articles to have a blank value for this new field.

This seems like it should be a simple task, but I can't find anything when searching for this issue online.
I just found this module: https://www.drupal.org/project/field_defaults

It seems like it might work. But I'll withhold accepting this as the answer unless there are better ideas out there.