The UEFI screenshot from the original reddit thread says this specifically:
BIOS PSP Support
Description
Enable/Disable BIOS PSP driver execution (including all C2P/P2C mailbox, Secure S3, fTPM Support)
and the QR code is the URL: http://www.asrock.com/manual.asp?Model=AB350%20Pro4
My understanding is that this an option to prevent the UEFI from talking to the ASP/PSP (AMD Secure Processor / Platform Security Processor). Nothing I have seen suggests that this is anything like the HAP disable option discovered in Intel’s Management Engine (ME).