I voted 40 yds. because I'm very confident in my equipment and my capability, not ego, facts... I also do all of my own bow work, and have done this at a professional level for over 15 years. My bow is not sitting on my wall, to just pick up, if something needs to be done. The work would have been done already lol. Again, not bragging, and I have pics/witnesses to prove it, but on a good day (for me) I can usually keep a 3-5" group @ 100 yds. (not willing to shoot that off the hood of my truck tho haha).
So here's my mental reversal. I have never shot a deer, with a bow, beyond the long range of 28 yds. Most of my shots are sub-15yds. with quite a few less than 10yds. I would feel "ethically comfortable" shooting an animal at 40yds. or less in "perfect" conditions, in the woods. Usually hunting is not conducive to "perfect" conditions or scenarios, and there's a lot that can happen on a live and aware animal. I'm fairly "seasoned" as a hunter, although I don't think that should be based solely on number of harvests lol.