There are three books I have been reading recently. Hunting high Country Mule Deer by Mike Eastman, Public Land Mulies by David Long, andThe complete Guide to Mule deer Hunting bySam Curtis. I believe any of the three authors would tell you to scout as much as you can and anytime you can. Western deer usually migrate and this is my situation. I have a tag for early november and the place I will be hunting will be waiting on the migration deer to arrive. It is 1200 miles from my home in Arkansas but I have already scouted by windshield once and on google nightly. There are some deer there now but I have't made any effort to see them. I think that a good buck in the area would have been poached by now anyway.
I like spring scouting best because you can sometime see deer in their migration, snow will have them blocked as it melts away. Summer is usually too hot and deer will be bedded shortly after daylight. I am hoping to be in my hunting area several days before opening season. If I can locate and get to see a buck that I want I will try to find his bedding area and his feeding area plus his escape routes. That said I will try to be back for another look in July/Aug.
My brother and I have done this kind of scouting recently in Nebraska and two years ago we were tagged out by 7;30 am. We were three air miles apart and 10 miles by road. These were just tag getters but the scouting was what made the hunt. My brother had made a shooting blind 250 yards from where he expected his deer to appear and other hunter (late arrivals) stopped to ask permission to go behind him for their hunt. I was at the edge of private property and when the deer returned to their bedding area they came by me while crossing the private property. I had to wait until the deer jumped two fences to be on public land and legal.
Your,"best time to scout" may depend on migration, weather, and time of season. I doubt the rutt wil influence scouting.