Hey @jvwcd, welcome.
The policy for the sparql endpoint is quite clear
maximum request rate = 100 (requests per second per IP address, with an initial burst of 120 requests)
In the last months we have worked on making it easier to setup your own SPARQL endpoint with DBpedia data; see e.g. Using DBpedia offline / Setup own SPARQL endpoint - #2 by jan and GitHub - dbpedia/virtuoso-sparql-endpoint-quickstart: creates a docker image with Virtuoso preloaded with the latest DBpedia dataset as starting points. This has the advantage that you have a quite fine-grained control on which data you would like to have and of course full performance based on your setup.
There is also a REST API which might be relevant for your use case GitHub - dbpedia/ontology-driven-api: An ontology-driven RESTstyle API for DBpedia backed by an external SPARQL endpoint which you can setup locally.
P.S.: BTW. We would be happy if the rest-api would be integrated in the compose setup of dockerized DBpedia as well, with a separate container/service. In case you (or others reading this) have some experience with docker (compose), this could be an easy way to contribute to the community 
Cheers,
Johannes