I ran a kitchen counter test with the Uncle Ben's: Poured 2 C near-boiling water over the pouch in a pot, and let it sit covered to simulate FBC. After 10 minutes it was still unacceptably crunchy. After another 20 it was still crunchy but tolerable (and bland). I poured off the water and it measured 1.5 C, so the rice had absorbed 1/2 cup of water.
This weekend I tried it for real - 4th of July dinner on the 3rd night of a Black Forest Trail circuit hike. I filled a 0.9L Evernew pot a little over half full with water, added a little salt and the rice packet, and set it on the Caldera Cone with about 3/4 oz of Everclear in the stove. The water boiled for almost 4 1/2 minutes before the stove burned out, whereapon I slipped the FBC cozy over the top of the pot (still on the cone) and left it until 10 minutes had passed since start of boiling. I then poured the water into the freezer bag of home-dried spiced lentils and kale, mixed, cut open the rice bag and added it, mixed again, and popped it into the cozy for another 5 minutes. An excellent dinner for two.