Portable RFID on battery for 12 hours plus easily removable data

However, I don't believe that a non-tech person would want to change a microSD in the dark in the middle of a cane field.

I do believe that you failed to disclose this requirement. Still, changing a microSD card is not that much more difficult than changing a USB stick.

I am aware of the driver issue with USB, but I do believe in miracles.

Probably believe in the tooth fairy, too.