At 1500 yards the difference in the point of impact between 0% humidty and 99% humidity will be about one inch.
Most scopes only work in quarter inch clicks so you would not even be able to make a humidity adjustment.
If you set your programs for 50% then you are pretty good to go.
I will say that a person should reasonably try to minimize errors but there comes a point where we are counting hairs on a frogs back.
There is also the problem of set up time. Getting an animal to hold still while we get everything done that has to be done for a long range shot is a problem. You will let animals get away at times because it just takes so long to get everythng done that is critical to be done. This is why a good spotter is so important. The work load is divided and you aren't peering at your drop chart or PDA or Kestrel
when the animal is walking into the thicket. Adding tasks to the to do list only increases the likelihood that you will not get a shot.
Rushing a shot with half baked data is the other extreme.