Yesterday, I nearly posted, but deleted it because I was lacking a "cool thing to do with a scripting language", but today I thought of one.
I know we don't have a super-combinator (yet), so we can't play 2 combinators simultaneously. But with manual effort, we could copy all the components out of one combinator, and paste them into another one, with an added mixer to mix them together.
So, now, imagine if we already had the ability to write a script that would do all of that for us. Then more scripts to remove the thing we added, or to swap combinators #1+#2 into #1+#3.