I have been able to be paid through payroll companies as loan out. These are the requirements:
1. Submit your company info to payroll through production. I have a LLC as S-corp operating in California. I have to submit my SOS and Articles of Incorporation.
2. Present current Worman's Comp. As a loan out, you are working under your own Workman's Comp policy, not the production company's. A standard Certificate of Insurance through your insurance will have a line item for Workman's Comp and this what I present to payroll through the production company.
This is additional onboarding work for production companies but most I have worked with have been willing to process this paperwork with payroll.