Thanks for posting this. Not only did SARA specifically reference the ARC report, it also includes a specific annotation in the findings:

(8) General aviation safety can be improved by modernizing and revamping the regulations relating to small airplanes to clear the path for technology adoption and cost-effective means to retrofit the existing fleet with new safety technologies.

Nothing would do more to meet that objective than reducing the cost of upgrades. Nothing would do more to cut upgrade costs than allowing non-TSO / non-PMA systems and parts. That points directly at the PNC proposal. I only wish they had called it out specifically as they did several other items in Section 3(b).