insert_many method calls frappe.as_json, which in essence is (source):
json.dumps(obj, indent=indent, sort_keys=True, default=json_handler, separators=(',', ': '))
I guess entire frappe package shouldn't be a dependence on such a small library, especially since it's only used to call this method. In other methods simple json.dumpsis used. Why cannot it be used in import_many as well?