A new nav card won't work. There's some secure/embedded info on the factory card that allows it to be recognized by the MFT unit. The copied card would not have it, and the unit would treat it just as a data card. It has been tried before on the Edge forum. But you idea IS certainly cool.

Ford A10 Navigation Card Download

After countless days trying to activate my navigation on my 2015 Explorer Limited, much help from the FORScan team (Thank you again for pointing me in the right direction), and numerous communications with a Youtuber, I have found a problem and solution. If you update your SYNC to version 3.10, as you know, you cannot reverse this. You also will lose your navigation (and I lost my 911 assist too). The patches to put it back all reference version 3.08. I have found a file from xda developers that repairs the navigation installation with SYNC version 3.10. I have followed all other steps (install navipatch, wallpaper, master reset, etc...), and then I found and installed this file. My navigation works. I love it. If you updated to 3.10, install your navipatch like normal (I think...you can experiment), reprogram your APIM with FORScan, master reset, install this file, and master reset again. You may not need to do this twice, I dunno. I only know it worked for me.

A lot can change in 12 months, and in the last three years over 1.2 million miles of new roads have been added to the navigation system map. That’s in addition to 1.5 million miles of updated roads and thousands of new points of interest. To purchase a Ford map update, visit the Ford map update site. Select your vehicle model and year from.
Friends with 2013-2016 sync 2 w/ navigation, Ford is sending out letters for their new A10 map SD card. Free shipping if you buy now!
Locate an empty USB drive that has at least 2 GB of free space and is not password protected. When you have a USB drive ready, insert it into to your computer and choose Start Download Process. When you have the USB drive ready, insert it into to your computer and choose Start Download Process. Follow the accompanying instructions on how to download the files and transfer them to your USB drive.

Many, many thanks to FORScan, XDA developers, and the guy on Youtube that FORScan team pointed me to (sorry, I don't remember your name at the moment).
File to download (just copy and paste in your search browser)
Ford A10 Nav Card Free Download

https://www.dropbox.com/s/1161ft2rs51ry ... G.zip?dl=0
And if that link doesn't work, here's to the page, just scroll to the bottom.
https://forum.xda-developers.com/window ... 080/page81

Ford A10 Navigation Card Download