The European Commission has published an analysis on the feasibility of digitalizing Diploma Supplements at European level.
The report analyzes the current situation, evaluates the usefulness of potential digitalization and looks at options for implementing it. It finds that digitalization would indeed be useful: It could “reduce issuing and handling costs, make the DS more secure and easier to verify, and add greater flexibility towards presenting and using the DS data. […] Having the DS in a machine-readable format could significantly reduce the amount of manual labour required.” (p. 5).
Erasmus Without Paper is mentioned in the report as an example of student data digitalization initiatives. Several positive aspects of EWP are mentioned, but the report also mentions some difficulties, for example that “The sustainability of the solution may depend on future funding” (p. 37).
You can download the report here.