I think it would be cool to have an ender barrel like the chest, but as a solid block. I'm not sure whether it'd be better to have the channels link with the chests or to have barrels be their own 'network'. I think either way could be cool. Either twice the channels available or more visual options for existing channels.

I'm not sure I personally agree with implementing barrels. I can see the reason to do so, however, I am having trouble visualizing how such a barrel would actually look. The top of a barrel is what opens when accessing the chest, but for Ender Storage, the top is where the nodes used to establish frequency are located.

Edit: On second thought, I do have a few ideas as to how I could make it work. However, I will leave it up to Covers as to whether or not to implement such a thing, as it would really just be a duplicate block. If it is desired, I can do some new art for it.