Short term -- I'll probably be moving to LibreWolf, most likely. I'm planning to spend a good chunk of time this weekend reviewing what exactly their fork does. I've read their self-description already -- and like it -- but I want to look through the code and try to build it myself before I start depending on it.
Long term -- I'll be keeping my eye on Servo and Ladybird.
Thanks for the pointer. As I said, I need to spend a good chunk of time reviewing exactly what they've done before I feel confident enough to depend on it. A simple reconfiguration of stock Firefox that I am confident does not phone home is likely good enough for me in the short term.
If you have a better solution though, please let us know what it is.
What I use is Firefox with config (similar to librewolf) + blocking using privoxy. I've been using this for a long time. However I'm no longer confident this is sufficient.