Have decided to give #ZenBrowser another go, but with conditions:
- #Sidebery, not its unreliable* & not-my-cup-of-tea native tabs
- #FirefoxSecondSidebar https://github.com/aminought/firefox-second-sidebar, not its unsatisfactory native #WebPanels
In case anyone wonders, this [temporary?] change from my hitherto daily 
[#FirefoxNightly + #Sidebery + #uBlockOrigin + #FirefoxSecondSidebar] has nothing to do with the recent global #FUD wrt Mozilla's #TOU / #EULA, but instead is due to the aesthetic pleasantness of 
& the desire to use its #SplitTabView #TabSplitView #TabPaneView; two undeniable advantages over Nightly.
* the Zen subreddit is full of users posting that Zen spontaneously lost all their tabs, or all their pinned tabs, or all their unpinned tabs. In my own past months of using Zen with its native #Workspaces & tabs, it also happened to me, twice, & it is most exasperating.
, but less polished than atm in 
have over stock 
, or else fork their fork [of FF] back into the parent product. 
provides several of the must-have functions so badly missing in