We recently got back and we were able to use the Military Memory Maker. I believe it was $98, and it was purchased at Disney Springs. My mom’s SO is retired military purchased it, but we explained to the CM that I have the MDE account and they linked it to my account right then and there. We also confirmed with them that all my immediate family’s photos for the whole week would be included (my mom and her SO were only staying at WDW the first 3 days), and it was no problem.
It did take a little bit of time to complete the transaction (maybe 10-20 min total - there were a few people ahead of us, then the purchase process took a little bit of time), this wasn’t an issue, but just wanted to let people know in case they are in a hurry.