To separate the use cases of evaluating a measure and collecting the data involved in the evaluation, a new operation should be defined:

$collect-data

The operation would have the same parameters and options as the $evaluate-measure operation, but instead of producing only a MeasureReport, it would produce a Bundle with the MeasureReport as the first entry, and any evaluated resources included in the Bundle. It would also not be expected to produce the actual measure calculation, enabling it to be used in scenarios where the measure cannot be calculated completely.