Ask any technician who works Aurora routes and they will tell you the same thing: the callbacks cluster in a handful of predictable places.
Snow load and ice damming stress the roof-to-wall junction each winter; by spring the sealant that was doing the work has usually torn.
The swing between a January cold snap and a February thaw can move a masonry assembly enough to open joints that looked sound in the fall.
Across Bayview Northeast, Aurora Village, Aurora Grove, Rural Aurora and Aurora Heights, the housing stock changes street by street, and the correct method changes with it. A century home with a soft-brick stack does not get the same treatment as a 2010 build with a factory-built vent — using one method on both is how systems get damaged.
the practical takeaway is that a dryer vent risk visit should start with an assessment, not a tool. Any crew that begins work before telling you what they found is guessing on your behalf.