So is this a case where the best route for a road might not be feasible because it's not the best route to clear with a BX? 1/4 mile is nothing to sneeze at if you're clearing with chainsaw and small tractor, so it might be a situation where you have to forgo the optimum path for a road and think mainly about the path that you can clear with your available time/tools/equipment. That means giving less weight to some of the traditional factors we use when picking the path of a road.
If it's really only to be a path for a UTV/ATV/BX, then just pick the easiest route to make the road. Chances are, no matter what path you choose, if you want to come back and make a bigger wider road for vehicles later on, you're going to need a heck of a lot more equipment than a BX anyway, so it will be a whole different level of effort whether you use the same path or make a new one.
When we developed our property, I made a path in for my (at the time) B2920. I picked the path of least resistance so that I could gain access to the area where I'd be cutting firewood and hauling it back out. I had to cut a few big trees, but it was mostly saplings that I could cut to a 2' stump and then use a brush grubber to yank the stump out. The path was just wide enough for the tractor. A couple years later when we put in a driveway, many other factors dictated the route. The middle of the driveway overlaps some my old path, but for the most part the driveway dictated its own route based on it's own considerations. At that point we had an tracked excavator and could knock down trees like toothpicks, so difficulty wasn't part of the equation.
Excellent point which is my biggest dilemma. I want to take the no hill route but due to much of this route being on the side hill may require more dirt moving / stump removal than I can reasonably do on the BX. The other route while going up and back down the hill is definately easier for the BX because the saplings are pretty small in that area less than an inch and the BX could push through easily with my pirahana bar on the bucket. Ill have to consider the slope on the hill trail as the limiting factor. I think another trip to site is in order.