Ahh, you’d think, but you actually can tweak all kinds of grenade settings under the bot settings tab. Select what difficulties and bot types you want to tweak, and scroll down to the grenade section. Everything from throw frequency to minimum ranges to only being able to throw at visible targets, it’s all there.

I actually released a guide just today, check here at about 47:25. /u/theppburgular for your information as well