How close or far from a private land boundary are you ethically willing to set up, trying to ensure you don’t lose a deer to a stubborn land owner?

With a bow, not close AT ALL. I like the question and will watch for replies.

I'd say 150 yards or so. As a deer can run a fair distance even with a quickly lethal arrow shot.
That said if you have a small tract you do the best you can. Also different tracts of land have different shapes and layouts. Always good to talk to neighboring landowners.

After my limited experience dealing with private land owners near public grounds, i would eagerly set up right by the fence line with a rifle. There are places where they block roads and run fences well into public grounds and that level of entitlement makes me want to invite everyone i know to hunt there. Some even put private property signs over the conservation area border signs. But with a bow i would give it a couple hundred yards unless i knew the landowner or unless hunting a very small public parcel. I would not risk losing a animal over his fence for fear he won’t let me go get it.

ditto, but them some people enjoy pissing into a 30 mph wind

Almost as good as pissing up hill....

I am a little closer (150 yards) to my neighbors fence than some, but I know for a fact he would let me come on if a deer I shot had gone onto his property. I would allow the same.

However, I have shot many deer out of that stand and some went down quickly some went down long ways away, and none have gone to his property. They always circle back to my property and go into the woods, downhill toward water or other trails. kind of weird to think not one has gone toward his property.

None of the land owners around me hunt, they tell me every year if i see something on their side to take it. One even put in a gate wide enough to get a 4 wheeler through so i could drive over if i needed to.

Good neighbors.

Its always good to start the conversation before season, rather than after the shot too.

I think it depends on the setup. Usually I would say pretty far way. If I'm in a situation where I'm in-between the fence and where the deer would be coming from, I'd set up closer and hope that he runs away from me after shot (deeper into public).