[nunwuo]

There's no faith required; the planner is guaranteed not to do that. The "normal" way is to create a composite type containing each of the columns you need, and then "unpack" it to separate columns. Horrible? Yeah, but it's possible.

[bchallenor]

Is it possible with scalar subqueries to perform anything other than a tree of correlation? With CROSS APPLY one can correlate a DAG of subqueries, e.g. a diamond where B and C depend on A, and D depends on B and C.