$env:$ tokens do not resolve within evaluation of a different token?

I'm posting this question mostly because it's maddening. I want a dashboard that is shared between two apps to behave differently based on the value of $env:app$. Doesn't work: If I run a search as follows:| makeresults | eval foo = if($env:app|s$=="myApp", "true", null())$result.foo$if($env:app|s$=="myApp", "true", null())if($env:app$=="myApp", "true", null()) The `$result.foo$` evaluates correctly but the other two return null regardless of the value of `$env:app$`. So with `$result.foo$`, or some JS I can get where I need to be, but why does it take running an extra search or script to get there?