The calculation for the Rock Gnome's Artificer's Lore feature in BETA 8 still incorrect. The current calculation is [Int (History) + int mod + prof mod + 2*prof mod]. The correct calculation should be: [Int (History) + int mod + 2*prof mod]. This follows from the text in the PHB: "Whenever you make an Intelligence (History) check related to magic items, alchemical objects, or technological devices, you can add twice your proficiency bonus, instead of any proficiency bonus you normally apply."
The current calculation does add 2x the proficiency bonus, but it does not remove the normal proficiency bonus. As a concrete example, my INT is 20 resulting in a +5 modifier, I am proficient in History, and my proficiency bonus is +3. Right now the bonus I get from Artificer's Lore equal to [Int (History) + 14] = [Int (History) + 5 + 3 + 2*3]. The correct calculation should be [Int (History) + 5 + 2*3] = [Int (History) + 11].
Thanks for providing this amazing sheet!