Hello community. Need advice about the best options available for this situation.

Scenario: External consultants thar are not employees of the company currently fill in an external form, so the company can pay them for their expenses. They are currently scanning these documents and bringing them as vendor bills to Netsuite. Bill Capture doesn't support them, so it is a manual process.

Question: What is the best way for these external consultants to track these bills/expenses directly in NetSuite?
Vendor Center Role only allows Purchase Orders and Requisitions, and the permissions can't be edited.
I've been trying to do some tests with the Advanced Partner Center, which by default doesn't have neither Expense Reports nor Vendor Bills allowed in the Role, but it does allow to add additional transactions under the roles permissions, so I've manually added them, but have not been able to do a successful test yet.