Hi Michael,
I cannot public the requested tool in a public space as the NXP community, you would need to create a Ticket in www.nxp.com/support so we can share this tool with you.
Latest hardware and firmware version is the PTN3460BS/F6Y and PTN3460IBS/F2MP.
There is no more detailed information about the Flash-over-AUX Communication and Mailbox other than the shown in the Application Note AN11606, but we can discuss further specific questions if needed.
Regards,
Jose