DMN12 — Show implied Information Requirements

It is easy to take advantage of the ability to have multiple DRDs showing the same objects to create multiple layers of detail - a high level DRD, more detailed ones for each "leg" etc. In general this works perfectly with decisions "encapsulating" their dependency network. The one thing that would occasionally be useful is an ability to see how Input Data is used throughout.
For instance, when Decision A requires Decision B which requires Decision C which requires Input Data D it would be useful to see that Decision A indirectly requires Input Data D. A version of a information requirement link that showed an indirect requirement would allow this to be shown without in any way violating or undermining the current approach to reuse across diagrams.

The scope of this issue is limited to "flat" DRDs, that is, no "sub-DRDs" nested inside an outer decision or BKM.

too difficult to do with diagram interchange framework

The DI framework can diagram semantic elements, but here there is no actual element, only an element that can be derived by transitivity. That is not sufficient for DI, and we do not want to materialize all possible transitive links.