Solved!
Ok, so I guess I will answer my own question!
I couldn't get the data from the card to be recognized by searching for the sd card directory from within Backcountry navigator.
However, I simply used a file explorer app and copied the tracks, waypoints, and trailhead folders from the SD card to the downloads directory for the tablet. Launched backcountry navigator, and now when you go to import the folders are listed and the data imports just fine with the tracks shown properly in the app. Sucks to import each track one by one, but in the end well worth it. I will chime back in after the trip and give my thoughts on how well this approach works.
