I was playing when I had noticed that in the Stonecutter menu Cut Sandstone blocks can't be cut down to Cut Sandstone slabs yet when I look at the crafting table menu Cut Sandstone blocks can be broken down further into Cut Sandstone slabs. If this is meant to be intentional, then by all means disregard this query.

It is a very minor thing to be adjusted and I just thought in the situation of someone accidentally cutting a stack of Cut Sandstone blocks and they need to break some of them down to Cut Sandstone slabs could do it much more easily while remaining in the stonecutter menu instead of having to go back and forth between a crafting table and stonecutter.