At the moment Wikimedia Commons Query Service (WCQS) allows SPARQL queries to look up stuff on wikidata using "service <https://query.wikidata.org/sparql>" (see Example) or in Commons categories using "service wikibase:mwapi" (see example). Unfortunately those 2 services only allow a limited number of records to pass to and from. Limit of service <https://query.wikidata.org/sparql> is in thousands or tens of thousands and limit on service wikibase:mwapi is 10k (see here)
The issue is that we now have 65M files on commons and we should expect similar number of SDC items. I would like to search all the wikidata items in SDC to detect redirects. That would require to send millions of item numbers to https://query.wikidata.org/sparql service. I would also like to find all the files in a category with millions of files that do not have some SDC property. Those 2 use-cases would require much larger limits on number of records sent to those 2 services.