I have not seen the haywire zooming even when running an app from inside Web AppBuilder Developer (is that what you mean by running for your C drive?).
Sorry, yes running from inside web appbuilder
You have never zoom go berzerk? I developed an app from scratch and was having that problem. Thought it was some outside services not loading properly but when I changed from.........
addLayers (layer1, layer2, layer3)
it solved the problem....... After weeks of head scratching and trying everything I could think of