Migrating from IDR to Payables Agent - AI Units cost implication

Summary:

Migrate from IDR to Payables Agent - clarification

Content (please ensure you mask any confidential information):

Our customer is using IDR functionality and considering migrating to Payables Agent features. Would appreciate if you could review my questions below and provide your inputs.
1. The Payables Agent seems to be using GPT OSS as the LLM and if we start using it as is, it won't be counted against the monthly AI units and no charges against this agent. We are in process of making this Agent available in customer's Test instance so wanted to ensure if there will be any cost implications.