Mick
As also implied by Luis and Daniel, I think this exercise has its greatest potential as a matter of intellectual curiosity.
With regard to the more practical considerations, I think your assessment makes perfect sense. Given the potential benefit of imbuing the solid with useful characteristics, such as the ones you mentioned, leveraging an OpenMode.ForWrite to also include orientation data is efficient.
One pitfall is when dealing with documents from other organizations. Many of which may not be receptive to outside routines, especially if required to run persistently.
My perfect scenario would be the development of organization specific routines which allows processing of non-standardized documents, thus avoiding any compliance requirements. This processing would couple Entities with material data (as derived from Layer, Tables, Xdata, or etc) in an internally consistent fashion.
Dimensional data would also be included in that processing. Asking the user to select the length for a given solid is the most sensible but has a few drawbacks; some of these projects use hundreds of extrusions, the task is somewhat monotonous, and that user is always me. Given that potential benefit, the exercise straddles the fence between curiosity and practicality.