Hi All,
Someone asked me what I did to mod the alu plate so that you could do split backspace and I figured i'd post it publicly for anyone interested. See below.
Here is what the plate originally looks like. It's a little grainy cause enlarged, but there are 4 "nubs" that cause the 2 switches to sit about 1-2mm above the rest of the row. You just need to grind these off.
Here is what the plate looked like after I ground the 4 nubs off. You can be pretty flexible about it, as the PCB will be holding the switches in place even if you grind off a little too much. My advice is to insert some switches in to the plate of the same row, then add your split BS switches after grinding a little, seeing if it lines up, take em out, grind a little more, stick em back in, see if it lines up, and so on until it looks right.
Hope this helps!