@Brad_Patterson had a bit of a breakthrough with this tonight - I was somewhat flailing at it at this point so I’m not 100% certain of precisely what fixed it, but you can see everything I did in this diff here:
I believe it was a combination of adding:
Install-Package Netduino.Foundation.Network
in addition to the base Foundation itself plus this line here:
which was based on the RgbLedHost example, and which contradicts both the documentation and advice I found in another thread here. I’m now able to successfully GET without any errors and everything is working as expected Maple-wise. I wanted to share this in hopes that it might help others - I can’t begin to describe the time spent and frustration endured to get to this point, only for it to be some trivial tweaks that just weren’t in the docs/were incorrect in the docs. Hopefully this helps someone else though … 
