Their Form 990s are hard to decipher (many many entitites) and they don't talk much about how they're structured or how they run their backend.

A big chunk was outsourced to Sun at one point. And that name alone should tell you how current the information is. https://en.wikipedia.org/wiki/Sun_Modular_Datacenter

In 2020 at least one public filing shows expenses of $19.9MM with $9.2MM classified as wages. So no more than $900k/month in 2020 and maybe double that now. Recent data is messy due to Covid donations and lawsuits.