<ul>
<li>I am curious, what is the purpose of printing a single-height outline around the objects to be printed?</li>
<li>Also, how would it affect the outline if the object to be printed extends to (very near) the very edge of the print area?</li>
</ul>

<p><a href="https://i.stack.imgur.com/vEr8Z.png" rel="noreferrer"><img src="https://i.stack.imgur.com/vEr8Z.png" alt="finished print on print bed, with outlines annotated"></a></p>

<p>Update, I received a hint that an existing question has the answer; that link was not really to my satisfaction -- but it did link to another one that did: <a href="https://3dprinting.stackexchange.com/questions/20/what-are-main-differences-between-rafts-skirts-and-brims">What are main differences between rafts, skirts and brims?</a></p>

My understand is that's is basically a purging extrusion, so that you get flow through the extruder before you start printing the object, as filament that's been inside the hotend during warm-up might have been "overcooked" by spending too much time in the hotend at temperature. It also helps stabilise the PID loop controlling the extruder temperature by allowing the PID loop to stabilise the temperature of the hotend as it's got filament flowing through it compared to it being idle.
It also shows the user where it intends to start printing, which is a useful check if something went wrong with Gcode generation.