yeah that should be possible. i am going to take a look at it soon

Alright sweet. Also, the Arrow Crafting Table is uncraftable if S+ (and probably Super Structures as well) if the vanilla Smithy engram is disabled for crafting. The Arrow Crafting Table is unable to be obtained outside of console commands or mods like Arkitect since it doesn't show up in the S+ Smithy or S+ Crafting Table. The forges also do not show up in the S+ Fabricator if I remember correctly.

Is it possible to allow these two structures to also be made by hand as a workaround?

Well thats a problem of the S+ mod because they replace the original smithy and fabricator. There is no way for me to integrate my items into the s+ smithy or fabricator. Also I had a quick look on the crafting recipes and it is a little bit more complex than I expected and thats why I probably wont integrate it in my mod. Sorry for that