I was just wondering if (or why not) the number from 1 to 10 block could have an optional step value?
You're supposed to make it yourself. I don't think numbers should be primative anyway. I can make one if you want.
We thought about it, but were trying to make it simple. There's one with a step input in the iteration library.
I like simple 
but...
99.9% of all looping contructs let you specify the increment/decrement step so maybe an option hidden by the little black arrow (I've forgotten what its called!) wouldn't complicate things (at least for the user)
Yes, if/when Snap! has the option for a "variadic" input where the only possibilities are none or one slot, that will open up lots of possibilities like the step option in FOR. (More specifically, we also need input grouping so that we can expose a prompt along with the slot:
)
I didn't realise that Snap didn't have that facility
We'll need to get @jens to have a chat with that John person over in GPBlocks
Well, you know, I was the one who wrote that feature for GP
Label groups is one of my favorite GP features that I haven't yet brought to Snap. The main reason is that in Snap we have variadic-ness on the input slot level, which is actually super cool (GP doesn't have that), and also - even more important - that in Snap! "empty" input slots can be mapped to implicit function parameters inside rings and unevaluated slots. In GP we never got around to doing rings before we ran out of funding, so we didn't have to deal with anything "lambda".
