Is there checklist for ISO 13485 document requirements specifically for a 3PL?

Answer:
There is no specific checklist list for ISO 13485 documentation for 3PL. However, list of all mandatory required documents for ISO 13485:2016 you can find at the following link: https://advisera.com/13485academy/blog/2017/01/18/list-of-mandatory-documents-required-by-iso-134852016/

Documents related to production, sterilization, design and development, installation, and service for your business are not applicable and can be excluded as such. For you, in addition to general procedures, the most important procedures are: Procedures for preserving the conformity of product (clause 7.5.11), Records of traceability and name and address of the shipping package recipient (clause 7.5.9.2), Report on Changes on Customer Property (clause 7.5.10).