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Develop as an add-on or as a DSpace feature
On the long term, it would be very neat to have this entire codebase/tool as an independent add-on, because it could make it easier for implementers in other repository systems to copy the code/approach, as opposed to dig into the DSpace core code in order to find the code for these features.
However on the short term the current DSpace REST-API may not be able support all of the required actions + the problem below with on-behalf of submission might be tricky to do from an external add-on...
Resolve conflicts with current DSpace logic
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