LOD Group Cross-fading duration?

Apologies if this is the wrong section, I just know LOD cross fades are utilized by shaders. I'm wondering if anyone might know how I can alter the duration at which a LOD cross fade occurs. By default it seems to crossfade by a quarter second or so. I'm wanting to stretch the cross fade closer to a couple of seconds.

 

If you disable the checkbox, a field will pop up that allows you to set the transition duration. Though in my experience, it's not always available, perhaps it was removed in newer Unity versions for some reason.

 

It can be set through code -

LODGroup.crossFadeAnimationDuration = value;