"Looks like Dadagoboi drilled extra holes in the base plate. Which shows at the E string side. The other is obscured by the saddle."
Correct. Also, I will be using FLAT HEAD #6 screws to hold down the base plate, at least on the G side, to get full adjustment. Oval head screws catch on the bottom of the carrier. You could grind the the center of the carrier to clear the oval head. But more trouble than it's worth IMO.