We will soon be needing a way to perform bulk actions in a simple way (i.e. import of CSV file). Our SAP administrators use this on a regular basis to provision (and remove) thousands of roles for SAP rollouts. We cannot provide them with the current midPoint bulk function as this is too powerful and too complex.
Ideally the format should be the same as the CSV export. The adding/modifying/removing of assignments may be tricky, but I will have a think and update this issue when I'm back in the office.