I do pay attention and steepness is part of it. Are there sluffs in the area? What are the layers like? Are the ropes up at the usually suspicious locations? But if there is a depth hoar layer down there, a 30* slope will bury you just as easily as a 45* slope (not quite as likely but just as easily).
Have been involved with avi control using the normal stuff; traverse, hand charges, recoilless rifles. Didn't ever use, or remember seeing the snow rangers ever use, an incline measuring device first.
Use them if you want to, just can not see the benefit.
Caveat! I did use my phone once to measure a slope while skiing. Had a bet going on how steep a slope was, and they bought the beer in the end.
It sounds like you are discussing inbounds avi control. I suspect that the controlled areas have slope angles that are known and that the treatment is done to known avi paths.
I'm talking about backcountry. Here in CO, our snowpack is terrible and if I can identify a nearly zero chance of a slide by determining that the slope is less than 20*, then I can ski said slope with impunity. The snow on the slope I'm referring to is nearly all depth hoar with firm layers from either wind, sun or temperature. So all the signs say 'no go' expect for the pitch.