Indexes can be used in an expression, but the logic is not always clear and there are no advantages over a regular chain, except perhaps to do obfuscation.
{“.query”: [“disabled=true”,“list=a”,“list=b”,“list=c”,“#|”,“#|”,“comment=d”,“address=d”,“#|”,“timeout”,“#!”,“dynamic=true”,“#&!”,“#2&1&0”]}
- in this example the expression “disabled=true” is ignored, “timeout”,“#!” - timeout is nothing, “#2&1&0” - changing the index order gives a different result, it looks like this is the “left to right” that documentation says.