Currently most of the exposed python calls return the whole instance of an object with all the data included, e.g. get get_reviews_by_project_id, while one can specify the return fields via the "fields" key inside the _get_json_response call getData dictionary.
Already speed-wise it makes sense to reduce the DB requests to fetch only what is needed, so an optional parameter to define return fields is a reasonable request. You can just pass on the list to the underlying getData parameter, maybe enforce that the ID is always present and ignore non-existing keys. That would be perfect to have already built-in instead of us using the protected/hidden _get_json_response call directly.
Seems like a simple fix, which would also reduce console spamming when doing command line maintenance besides optimising script requests.