Something to consider in regards of the sound of a cordless drill spooking deer.
September of 2017, I pre-drilled my first tree of the up coming season. After drilling ten holes I came straight down pulling bolts. As soon as my feet touched the ground I looked up and saw three rack bucks traveling the edge of a thicket no more than 30 yards from where I was standing. This couldn't have been more than 30 seconds after I had drilled the last hole. Even though they were traveling, I believe that they had to have heard the sound of my drilling.
With that said, I believe that deer associate danger with bad experiences though scent, sounds and sightings. Evidently they hadn't had a bad experience with the sound of a cordless drill motor. Even with that experience I've never drilled a tree with a cordless drill motor and immediately hunted it. But, I have drilled numerous trees using a cordless drill and a day or two later hunted them with some positive experiences.
I've hand drilled hundreds of trees since 1983 but have fallen in love with a cordless drill motor. I always have my hand drill with me but only use it on rare occasions. The difference in drilling a hole is 5 seconds with no effort and 30 seconds with effort. At my age I choose the 5 seconds with no effort method.