Can the REST API be used to get custom fields from inventory numbers?

I’m using the query /suiteql endpoint.

https://#######-sb1.suitetalk.api.netsuite.com/services/rest/query/v1/suiteql/?limit=20

The body queries an inventorynumber.

{ “q”:”SELECT * FROM inventorynumber WHERE inventorynumber.inventorynumber = ‘500730’” }

The result does not include any custom fields for the inventory numbers.

inventorynumber result, no custom fields: https://gist.github.com/james-grumish-fjorge/80ce38f6e2aad1ef6a0cfd2df235ffc7

This result is different from queries for items, which include all custom fields.

item result, all custom fields: https://gist.github.com/james-grumish-fjorge/f1690762e11bc95174fa80fa174ba2f1

Is there a way to get custom fields from an inventorynumber query?