[7/13/2021 update - Part 2 added, see second post]
I've gotten a bunch of messages and gave a few empty promises (sorry guys) that I'd write this up. Life got busy and I haven't had time to tinker with my w4500nex, especially since I traded in my Jeep for a well-equipped Ram (that 12" screen is both awesome and underwhelming). I haven't played with this since but I figured at the very least I could give you a how-to so you could get your radios back online and hopefully someone can build up
Thanks @DatsunĀ It seems our images are different in some way.
For others viewing this topic, I purchased one of the official Pioneer SD cards for the AVH-W4500NEX from PacParts.com. Part number QXX3352 (https://www.pacparts.com/part.cfm?part_no=QXX3352&mfg=Pioneer).
I created an image from the card using this command(in linux, MacOS can do this too):
dd if=/dev/sdcard of=/path/to/image.bin bs=512
and then hashed the resulting file with this command:
sha256sum /path/to/im