[ShadowChemosh]

Originally Posted by Jobe00

Is there a way to script it to have the flat character level damage bonus show up with the Sneak Attack dice in the Specials tab ala "Sneak Attack +xd6+y?"

So if you do a "New Copy" against the Sneak Attack Class Ability you can view the scripts. We see that the script at Render/10000 it sets the livename:

field[livename].text = "Sneak Attack +" & field[abValue].value & "d6"

So with this idea we can modify the livename again after Render/10000 to add your additional Plus Level damage:
Render/10100

~ If this feat has the disable tag, get out now!
doneif (tagis[Helper.FtDisable] <> 0)
~ If the Sneak Attack class special is not live than get out now!
doneif (hero.childlives[cSneakAtt] <> 1)

~ Calculate the characters total level using the level macro
field[abValue].value += #totallevelcount[]

~ We need to append level damage to sneak attack class special LiveName.
hero.child[cSneakAtt].field[livename].text &= "+" & field[abValue].value

The above script would go on to your feat at Render/10100 and will only run if its not disabled and the Sneak Attack class ability is actually present. Then in example at level 1 the livename of the ability is "Sneak Attack +1d6" so we simply add to that name making it "Sneak Attack +1d6+1".