Assuming that a C2C is a 1099, then it's best to track that as the fill for the position. Ensure to note the type of fill (i.e. "C2C"). Item 19 on the itemized listing requires compensation data for "contract" employees, but does not define this term. In my experience, it is best to have the record than not have it, so I typically recommend to track such an individual, so no, not wrong to track in ATS. "19. Employee level compensation data for all employees (including but not limited to full-time, part-time, contract, per diem or day labor, and temporary employees) as of the date of the organizational display or workforce analysis."
You can use this OFCCP audit checklist to ensure you're doing what is required to maintain OFCCP's regulations including VEVRAA, Section 503, and EO 11246. Or request a demo to streamline your compliance and recruiting efforts.