I disagree with your assessment of importance. A work like this strikes me as being primarily important as a "concept of operation", with sketched numbers from (presumably) sub-studies. In other words, my primary concern would be Does the whole thing hang together? Hard to say for such a vast project, so you need to start somewhere with many estimates and placeholders. I wouldn't shoot down the value based on missing references for sub-projects. Especially for what appears to be a solo-author work.
I do agree those would be helpful references. I've contacted the author asking for collateral materials and will post back if there's anything to share.
The validity of the concept of operation depends entirely on the validity of the assumptions that went into it. If, for example, the truss building unit can't actually make truss much faster than an appropriately designed spider working directly, or if the project would be done before the TBU could be completed, then suddenly the argument for spending a lot of resources building the TBU disappears. Yeah, you gotta start somewhere, but this isn't the place to start.
I do agree those would be helpful references. I've contacted the author asking for collateral materials and will post back if there's anything to share.