I've seen in the API Reference, QuantRocket supports also Quandl databases.
At the moment only two databases are supported: Zacks Equity Prices and FinSentS News Sentiment.
What about adding support for the "Sharadar Equity Prices" (SEP) and "Core US Fundamentals Data" (SF1)?
They have a long history (ca. 16 years), are survivorship bias free and very affordable! (expecially compared to Zacks).