With all the crazy ways trees have been taken down over the years, I'm still trying to see the down side to this idea. If it's a straight spar, whers the problem? He can get to it with the stand, tie himself in with a flipline and harness of some sort and work from the treestand platform. Wheres the problem? If he's dropping it to the ground, bombing it I think is the term used in here, so be it. And if he's tying it off to lower it down slowly, so long as it drops and clears the stand, (rope and log), where's the harm other than the purists that demand that all the "rules" are followed and all the gear is used? I would think the biggest concern is the weight the stand can hold. They are rated for certain amaounts of weight so if the person + gear + log weight is more than the rating, danger will follow.
And from someone that spends hundreds of hours in treestands during hunting season, they are as safe as the person in them wants them to be. Falling out of a stand usually happens when someone falls asleep or slips on ice buildup and on occasion, trip ups and isn't tied in to the tree with a harness. The stands themselves are safe. Its the people in them that are unsafe.