Hate to say it, but you may not find anyone willing to pull their SD card and attempt to make a backup image - know I'd be hesitant to pull it. Might be best to reach out to Stern.

if you try to update the unit via usb with the sd card formatted, would it rewrite the required data back on the sdcard?

I've got a premium/Le image if that helps?

I wouldn't put that in a pro for fear of doing something very bad.

LTG : )

While you're waiting, make backups of all your important data.

You can't just copy it, it has protection or hidden sectors,
you need to use a program like this to create a raw copy file.
http://hddguru.com/software/HDD-Raw-Copy-Tool/
(you can make a raw copy to a file on your pc, so you can easily create a new sd card)

I would advise everyone to make a raw copy of the sd card on everyone of their spike-pin.

The good thing is, if you do that, it keeps your settings and highscores from the moment you do the backup.
If you use a copy to do the upgrade, you can simply downgrade in seconds by switching the sd cards.

So maybe someone can make a raw copy of their gb pro sd card and then send the file with "wetransfer" to ahdelarge ?
(Sorry mine is a gb le)

or

dd if=/dev/sdX of=/dev/sdY

https://en.wikipedia.org/wiki/Dd_(Unix)

Take the LE SD image being offered and write it to your card then do the software update from stern on the card to get the latest pro software.

Stern should definitely be putting that kind of image out there for an emergency fix. Hell, they would be able to throw something together that is stripped down and only boots the update code so that there wouldn't be any worry about what the node boards might do if in the wrong machine (if that is even an issue?).

I always backup the current image on my Spike games before doing any update in case I want to revert back. Here is the video I made showing how to backup and restore the SD card for Spike games.