So that's a pretty terrible idea, and I knew it was crappy when I wrote it down.
To recap: the fundamental operations like PICK operate in the "mostly unbound world"... and mechanically pick things without having them bridge the binding from the container onto the thing you picked. I was looking for some other place to put the cue--so your PICK product could have a binding, without needing to do further operations on it.
Treating $[...] and [...] differently as the thing you are PICK-ing out of is bad, they're conceptually just lists and you shouldn't worry that your code is going to act differently on basic operations like PICK on them.
But the good thing about writing down terrible ideas is helping you see where the modification needs to be made to make it non-terrible.
When that post was written, $1 was a MONEY! and there wasn't a generalized Sigil system. BUT NOW... that idea of MONEY! is dead, and we can put [$ ^ @] Sigils on anything and everything... e.g. $1 is a "TIED! INTEGER!"
How about THIS:
>> x: 10
>> block: [x y]
>> get block.1
** Error: X not bound...
>> get block.$1
== 10
>> get block.$(2 - 1)
== 10
cc: @bradrn