I like to hedge my bets. I have ten foot high wooden shooting towers set up around my lease. Most are back to the woods facing a meadow or agriculture. I figure if they come into the open from behind me, some sort of scent control or cover may help, unlikely to hurt.
On numerous occasion I've had Deer come up behind me in the woods, walk into my scent cone and take off in a panic, the Doe are prone to bark. This spooks every Deer within 1/4 to !/2 mile or more. If I use a cover scent they rarely panic, they may be leery of the new scent but they are less prone to panic.

It may be different Deer to Deer, it is usually the spookiest Deer around that makes the decisions for the others nearby. If one spooks everybody is likely to spook.

I mostly ambush hunt, most often last light and get the early risers moving from bed to food. Or first light on a trail when they are moving from food to bed.

Like I said, I hedge my bets, you never can really tell when and where a Deer is going to pop out and appear. If they come up in or near my scent cone a little scent precaution my just help in some small way.

Another observation is in some cases how much scent or how strong it is makes a difference. They may tolerate a little, a lot may really put them off. I think of human scent kind of like a pile of poop, sometimes the closer you get the less tolerable it becomes. Not a rule just a tendency I've observed before.

After years of observation, most wildlife knows you are around when you get within a quarter mile. People tend to think of Deer in a vacuum, there are other animals out there eye dominant, not nose dominant and they tip each other off to danger.