Receive Large Pushes from External Source

I am trying to receive a push from an external source (Oracle Fusion I believe). Initially we tried this via streams, but the payload did not conform to standard stream schemas. We tried listeners next, but some of the json payloads exceeded the 1 MB payload size limit (maximum payload is ~5 MB). I am experimenting with custom endpoints next and compute modules, but I couldn’t get either working. Does anyone have any other thoughts of what to try? Or an idea on how to get compute modules working?