OX plates extra holes?

I notice that the OX gantry plates, at least the ones @Brandon_Satterfield sent me, but also on the official drawings, have an extra set of holes in front of the slots that hold the X rails between the gantry plates. It almost looks as if they are intended to accommodate using three 20x60 X rails bundled into a 60x60 pack.

I don’t plan on doing this now, but I’m just curious whether changing the wheel axis bolts to ones 20mm longer and adding a 20mm spacer in between the wheels in order to use an additional cross beam is a thing that people do on the OX, or if those holes actually have a different purpose.

People used to put 90 degree blocks in those holes to the 20x60. Considering the moment arm, they serve no purpose but some people were dead set on, they served a purpose, so they remain.