Realize that reality is that your simply talking about shooting at some type of target, and not a live target as in hunting. Especially in the east, the conditions for seeing clearly and shooting even to a mile is not very likely during the rifle hunting season in Pa.
As for balistic statistics, they sound good but reality is that they dont always look as good as they sound in the real world.
You have seen first hand what your cartridge can and cant do, at least well, and there is no better experience than actually seeing it and not just reading or hearing about it.
For decades, one of the most sought after cartridge among LR hunters in NC Pa was the then wildcat 30x378.
For about 25 years i used one on a large custom action sending 200 gr SMKs @ 3500 fps.
One day during the season Bruce showed up where we were hunting, and not long after that the hunting stopped and the shooting started. I found out just how good my gun was when compared to his 338 at even 1500 yards, and for accuracy especially.
The larger cartridges will make you into a better shooter at longer distances, that simple.
As for the initial question on the Kestrel, within a small area from our camp, there are lots of other camps who hunt long range. I personally know quite a few of them, some for a very long time, and frankly i dont know any to be using a Kestrel.
Now in fairness, very few people there hunt solo. Mostly in small groups from fixed locations, and always using large glasses on a tripod, which means spotters watching for hits.