There was an issue with Zen about a year ago, it used to send Mozilla telemetry requests, and the developers had ignored any complaints on it. Anyone knows if the situation has changed since?
I found nothing on how private Helium is. People usually just say it is garbage because of the engine, but that’s not what I care about.
From a non-technical user, Helium ships with the Manifest V2 version of Ublock Origin and has all forms of telemetry removed. So it’s more private than the base Chromium browser. I switch between Firefox forks and Helium, depending on whether a specific website works better in a chromium browser or not.