I think your question epitomizes the importance of innovations such as Hyperloop in transportation. By creating new transportation processes, different components of a technology can be applied elsewhere and enact further change.
During my research I too was considering how the specific efficiencies and optomizations of Hyperloop may be applied to HSR, but I came to the conclusion that these efficiencies are unique to Hyperloop. For example, the concept of reducing air resistance by inducing low pressure environments is ideal; however, the Hyperloop system is designed to not only operate in those conditions, but is rather optimized for them (particularly compressing air in front of the capsule and using it for suspension). The same optimization is not present in HSR.
Having said this, construction processes are definitely an exciting area for growth. Offsite construction is emerging in various industries such as housing, and is worth exploring in transportation. Perhaps offsite HSR would be valuable, and principles from Hyperloop can be applied. Overall, I think Hyperloop is a spark that makes us think differently about transportation which I think is the most valuable outcome of the proposal.