On the other hand, there is no need to bring the water to a boil to reconstitute dehydrated food when FBC'ing.
Hot water yes, boiling no. I've learned what to look for that tells me when the water is hot enough, e.g., vapor appears out the spout of my Primus kettle, a 'sound' indicating the bubbles on the side of the kettle (pre-boil) are starting to move, etc. A minute or so after those hints, the water is plenty hot for dehydrated food. In kitchen testing, that's about 185°, probably cooler on the trail but I'll bet never hotter. Of course, as the water is poured into the baggie, it's cooler even still.
Learning to use a stove set up (I use a soda can alky stove and the Primus tea kettle) like this will save fuel and maybe time (I imagine cooler water lengthens the reconstitution time but I've never compared...). It also keeps the water temp at or below what some baggie manufacturers have recommended...a possible benefit if one is concerned about toxins. However, I've always had the impression that the manufacturers' recommendation was from a burn safety and baggie melting point concern, not toxics.
From testing and trail experience I know how much alky to put in the soda can stove to get my two cups of water to temp...light it up and when it burns out the water is ready. Kept in a cozzie while 'cooking', the meal is usually pipeing hot when ready.
Temps, expectations and results should be adjusted for high elevations, i.e., near-boiling water won't be as hot. All my experience has been under 8000'.
FB