Both the Streamliner DLX and Road DLX are similar in construction, being the DLX has a 3.54" top base for trunk bag versus the narrower road which I think is close to half that.
I have the DLX model; its right in front of me on my bike at this moment. The stiffness of the rack is measured in how much side to side motion it can resist and the weakness of the streamliner series is those thin plates that hold the rack in place on the skewer. 110 lbs is static weight pushing down. Not doubting that it can not sustain that load, but most of the time, it is the dynamic side loading stress that breaks the rack stays and welding. My older OMM has a dynamic side loading of 30lbs (this is more realistic), but the plates and attachment points are way way thicker than the Streamliner. I suspect the Streamliner only has a side load capacity of 10 to 15lbs and judging from reviews of people overloading it with 20lbs and my own experience bending the stays to the side which you can because there's nothing stopping it from moving side to side as opposed to OMM racks, the stays can break through repeated bending from left to right like a paperclip with enough twisting. This is true if you have panniers loaded on its sides. If you have a 20lbs load strapped on top, then this will be different. I had since moved my DLX to my folding bike as the much lower center gravity, light, extra vertical stiffness for the price and my ability to carry front panniers means I never exceed the 10lbs on the rear.