Want Idiot Savant to scale upward with your SPECIAL scores instead of downward? This does that. This mod comes in four options.

Savant: Scales upward with Intelligence.
Street Smart: Scales upward with Perception.
Chosen One: Scales upward with Luck.
Smooth Operator: Scales upward with Charisma.

There are a few other mods that do something similar, but mine importantly differs in two ways:
1) I account for scaling all the way to 20 in the relevant score. It's very difficult to go above that, but it's easy to go above 10, so I wanted to accommodate.
2) I have fixed the issue with rank 3 Idiot Savant shutting off the other effects when it's active. This was annoying and made rank 3 actually lower your average experience gain. Now the chance for bonus experience won't shut off while you have tripled kill experience active.

I personally recommend using a mod to remove the noise the perk makes when it triggers. Like this one or this one. But some people like the sound, so that's up to you.

Installation:
The download includes all three files because they're tiny. Pick the one you want and shove it into your Data folder (likely located at C:\Program Files (x86)\Steam\steamapps\common\Fallout 4\Data). Make sure your My Games\Fallout 4\FalloutPrefs.ini file has the line bEnableFileSelection=1 added at the bottom under Launcher. If you have the beta patch, you'll also have to manually add this to your C:\Users\User Name\AppData\Local\Fallout4\plugins.txt file and then set it as ReadOnly.

OPTIONAL:

• By request, all three are also available in a version that has no level requirement.
• If you don't want to reverse the Intelligence progression, but you do still want a fix for rank 3 shutting off rank 2, that is also available.