Been on latest version of AWOIAF and I'm around day 60 with a personal riding skill of 4. When I equip and unequip horses, I know longer see the horse's stat increase to my hero's riding level. In other words, none of the horse's stats increase when equiping to my main character with a riding level of 4
I'm not the developer.
What exactly is your "horse's stat"?
Do you mean that the value (of horse's stat) will change while your character's riding level is below 4, and then it will stop changing after level 4?
Is the changeable stat displayed somewhere? (If so, what steps result in it and where is it displayed?)