I think you should make it a new kata. Modifying my solution so that it would print out the pieces would be non-trivial.
It is basically the literal translation of what I did in Python (or Ruby): if you have test=[a,b,c,d,e,f], to get, say, a-d in Python you would write test[0,4]; in js, lacking much of that sweet syntactic sugar, you write test.slice(0,4).
Fine by me (I didn't know who put the randomized test, which made little sense to me and left them out of respect).
And glad you appreciated my work :)
The last test case property $ \a b -> checks random integers. While one can add corner cases (which I recommend), your cases should be covered by the random one.
property $ \a b ->
I don't think that's necessary.
Checkout the Kata Best Practices section for how you can go about doing this. We don't really support kata chaining but you can use a prefix to help identify kata that are a part of a batch or theme. The recommended kata section will show them when viewing a kata's details. Its not exactly what youa re looking for but its the closest thing that we support at the moment.