How (much) can I minimise the cooking time of red split lentils?
I can’t give you numbers as I haven’t experimented with it yet (but am very inspired to do so by your post), but assuming that you will be heating water for a morning coffee or so, have you considered putting the lentils into a smallish thermos container, topping them up with boiling water and letting them soak / slow cook during the day? Adding your dehydrated veggies and spices wouldn’t require any serious cooking at all, just a quick reheating or bringing it back to a boil.

The idea is roughly based on the principle of a haybox, where food is cooked by placing the hot out into an insulating environment. And combined with the “quick soak” method for beans, where the beans are not soaked in cold, but boiling water, but for just thirty minutes instead of overnight.

Admittedly, this would probably get the lentils in the danger zone for longer than the canonical two hours, but on the other hand, we are not dealing with proteins like meat, raw eggs or dairy. But you could always adjust the time when you start the lentils to fit stricter food safety guidelines or your personal risk tolerance, e.g. boiling the water at your lunch break.