The internal audit requirements of ISO/IEC 27001 apply to the PIMS, so internal audit must test conformity and effective implementation of the privacy extension as well as of the security management system.
ISO 27701:2019 5.7.2 is one control. If you already hold one of the frameworks below, a reviewed crosswalk already says how much of ISO 27701:2019 your existing evidence covers. Hold SOC 2 and 58 of 108 ISO 27701:2019 controls already carry evidence.
Each report names every control your existing framework evidences, every one it does not, the reasoning behind each claim, and the claims that were argued against and rejected. 289 were rejected on the SOC 2 pair alone.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.