Oh, I thought IceWeasel had been renamed to IceCat, but the repo you linked to has recent activity and calls it IceWeasel, now I'm a bit confused. Glad to see it's active though.

The Gnu Icecat is still active as well.

Compiling Firefox without telemetry is just a flag, as we discovered while doing something over the debugging interface not available in the Windmill Test Framework. Tip: running profiles off a ram drive reaches ludicrous speeds.

Tor Browser also works: https://www.torproject.org/download/languages/

Best of luck =3