This is an intriguing idea, I have a few follow up questions about it.
Could you provide some example of datablocks that you would create if you were able to specify two report suites within a datablock?
Do you need this feature from a productivity perspective only (it is faster to create one datablock than two separate datablocks)? Or will it unlock specific functionality that is not currently available?
The use case I had in mind was in answering questions about traffic across many different report suites (aka at the enterprise level). Seeing that all in one Excel Worksheet, with the RSID as a Field would be really valuable from both a productivityand functionality perspective. Otherwise I'm creating 50+ data blocks everytime I want to ask an enterprise question. Hope that helps.
FYI, we do have a global RSID which we use on all pages of every site however it's more powerful to select which combinations of RSIDs I want to combine in a pull rather than to have to create filters.