Get Folder Tree by Custom Item Type ID

Hello! For various reasons, we're having to leverage the Wrike API v4 for our implementation (i.e., data load) and different, custom automations that aren't available "off the shelf".

Creating work items, then immediately updating them based on the ID provided in the response, is easy--leveraging '/custom_item_types/<cit_ID>/instantiate'.

One area where we're struggling is the ability to query for and/or update items, based on their CIT. Similar to the ability to Get Folder Tree by Custom Field, what's the method or suggested process to Get Folder Tree--by Custom Item Type?

Thank you!