Just had my original Hankook's replaced with Defenders after 57k. Literally just got home from Mavis and realized they are 110 not 114. Their website shows 110 as the option. Is there a danger in running the 110's instead of 114's?
In theory, yes.
The load rating of a 110 tire is 2337 pounds. The load rating of a 114 tire is 2601 pounds. Obviously, the load rating is the weight that tire can bear. While the 264 pound difference doesn't sound like much, remember to multiply it by 4. So running 110s instead of 114s, you have lost more than 1000 pounds of carrying capacity. (The pressure to which you inflate the tires play in here as well, but it doesn't help.)
The 114 is necessary for these vehicles because of how much they weigh and how much they can carry (if you were to load 7 adults in the vehicle you would likely be close to the stated payload capacity and, by extension, certainly over the capability of those 110 tires).
If you go over the load rating of the tires, you will wear the tires faster and your risk of a blowout is arguably higher.
I have always been told you can buy tires with a higher load rating than the OEM tires, but you should never go lower.