MODX3: how to tell new MODx.window.CreateResource (from tree) to use a custom processor?

If enabled in settings (enable_template_picker_in_tree) MODX3 uses a new method to create resources - a quick create window.

I’m refactoring a MODX add-on (GoodNews) to work in MODX 3. As GoodNews uses 2 custom resource types (GoodNewsContainer & GoodNewsMaling), I decided to create a MODX 3 standalone version.

A GoodNewsContainer needs to be created from tree. The problem is, I’d like to store some default properties for this container-resource when created. So how can I tell MODX to use a specific processor (extending the default resource-create processor) in this case?

The “old” method of creating a resource (using a full page) is working fine.

I had a look at the MODX 3 versions of Articles and Collections code, but they do it only using the old method.