The back quadrant is going to be a workshop area, and as you pointed out there are three inner beams, It is also where I have two 4' by 5' windows. I will finish that next summer. It will also provide a little support for the snow in part of the building, but the trusses are
over engineered at 80 lbs per square foot for the snow load. My original garage collapsed under the snow load, so I am more conscience of snow loads than your average person.
Here is a picture of the inside of my 24 by 42 garage which I took on 3/8/2001. You can see how high the snow is by looking out my 7' garage door and window. Most people in the U S don't understand the concept of really deep snow. It effects how you build things. Note the three courses of block that are under the walls. You do that to minimize the problem that would occur by having the melting snow up against the wood walls.
So are you and engineer (i.e., MTU grad)?