In the 0.3.0-draft stdio.wit, the (currently undocumented) set-stdout and set-stderr functions raise the question of what happens when they are called more than once (either by the same component or by multiple subcomponents of a composed component). Will the last call overwrite any previous calls? If not, perhaps we should rename the functions to e.g. add-stdout/add-stderr and document that the stream parameter will be added to the set of streams sent to stdout/stderr rather than replacing the previous stream.