[Java AUT / JavaScript test] .Exists waits when window exists but is not visible

WaitAliasChild does indeed always return immediately.

Your statement "Property Exists will return immediately" is, however, incorrect (At least in my case)

It will ONLY return immediately if the element is visible.
If it's invisible, it will wait for the default timeout

WRT the enclosing of an if statement - yeah, in production code, I would indeed do that. For the sample code, however, I KNEW whether it would return true or false, I just did it that way to keep the sample code shorter