Don’t have to hypothesize, although I was not lost, I did undertake this similar scenario a few days ago, using an XM-L2 Spark ST6NW on High mode for more than an hour and a half by which time the sun had some up and I switched it off. (I also use a Spark SD6 with the optional flood lens, clipped to my hipbelt for these sorts of exit routes so that I have good preipheral vision, handy and comforting when the bears are active in the sub alpine digging up hybernating Columbian Ground Squirrels). It would appear that Google ‘My Tracks’ got confused however, the moving time was almost the same at the ‘total time’,
A diffuser is probably the best way yes.
You can also simulate a sort of flood by holding the light at a very low angle and stretching the hotspot out on the ground. This produces a narrow-but-long evenly lit area of course, but it also helps diminish the contrast between the hotspot and the spill a little bit and gives slightly better side-to-side evenness as well.
It’s not ideal obviously, but it works surprisingly well in a pinch.
I was in the Amazon basin several months ago where it’s pitch black at night. Nothing gets through the tree canopy at all. In my opinion any decent light with around 200 lumens or greater and sufficient runtime would work in this scenario. And throw was better for me than flood. I had a Convoy S2 in the hand and Zebra SC52 on my head and I greatly preferred the Convoy.
So the key points for me in the light are 1) reliability, 2) runtime, 3) brightness, and 4) tint (T5 being better for seeing in the forest). Any decent 18650 or multiple AA light should be able to cover all these points.
Think outside the box… 
…That isn’t a light!
Fenix TK70!
It depends on what you are trying to do. I’m generally hiking so I want flood and it doesn’t need to be very bright but it’s nice if it lasts a long time.
Maybe if you are a hunter then you are more concerned with throw.