The FBC meals I make for breakfast only need to have hot water added and few minutes sit time. I eat cold the rest of the day till dinner - but I am in camp when I make dinner. Boiling water is 5 minutes, 15 minutes in a cozy. Not sure how your meals are taking longer? 20 minutes isn't a huge gap of time - considering if you did actual cooking you would have boiling time, cooking time and then cleanup?
Or do you boil water for 3 meals a day?
Honestly....if I have hiked 15 to 18 miles in a day, by that point I am ready to sit down and take my time ;-)
Then again....while making your meal do other chores - make the most of your time. If your water is on to boil, then go fetch water for your bottles, set up your shelter if in camp, etc.
You shouldn't be using up more than say 40 minutes a day for cooking - if you count boiling/cozying time.
And ask yourself - if you are up at dawn and hiking till near dusk....does it really matter if you sit down for a short hour a day to eat? Enjoy the hike! Part of hiking is loitering - something many of us often forget......take a break by a lake, on a pass - enjoy the view. Take off your shoes and let your toes cool off while you eat!