If you've got an SSD, slap it on there asap.
The horrible design implementation means that the only way to compensate for KST's shortcomings, is to use more/better hardware than it should realistically need.
Imagine everything that can happen in any one location in the game, including those limited to certain times of day.
They're all being loaded in at once, then whatever's not the chose scene, gets hidden from view. This happens each, and every single time a location is visited, i.e. you leave a location and go straight back to it.