In honour of New Coke's temporary return to the market (by the way, I say it tastes like Pepsi and my father says it tastes like RC), I failed again with this release to get some sort of async/await support off the ground, and we are still plagued by issue 533. The second should be possible to fix, but I don't know exactly what's wrong. The first is not possible to fix without major changes because it reaches up into the browser event loop, but should be still able to get parsing and thus enable at least partial functionality from the sites that depend on it. That part didn't work either. A smaller hack, though, did make it into this release with test changes. Its semantics aren't quite right, but they're good enough for what requires it and does fix some parts of Github and other sites.
However, there are some other feature improvements, including expanded blocking of cryptominers when basic adblock is enabled (from the same list Mozilla uses for enhanced privacy in mainstream Firefox), and updated internationalization support with upgraded timezones and locales such as the new Japanese Reiwa era (for fun, look at Is it Reiwa yet? in FPR14.1 before you download FPR15b1). The usual maintenance and security fixes are (will be) also included (in final). In the meantime, I'm going to take a different pass at the async/await problem for FPR16. If even that doesn't work, we'll have to see where we're at then for parity purposes, since while the majority of websites still work well in TenFourFox's heavily patched-up engine there are an increasing number of major ones that don't. It's hard to maintain a browser engine on your own. :(