For those interested, there is now a Telegram Group for Nightly Testers. It is my hope that we can put out calls for features and other items to test. We will also delve into stability issues since it is important we identify crashes early and get them fixed.
Please feel free to join if you are interested in discussing what is going on in Nightly (Both Desktop and Mobile). Currently both @mozillamarcia and @gaby2300 can add new users to the group.