> which I believe already include the speed improvements from 57+?
Interestingly Firefox Focus uses WebKit (/Blink?), since that's what Android's webview provides. Firefox for Android should get the improvements around version 58 or 59.
Also good to note, for people planning to stick with an older Firefox for as long as they can: Firefox 52 is an Extended Support Release, and as such will actually be actively supported until June next year. This will give WebExtensions some extra time to mature for more use cases: https://www.mozilla.org/en-US/firefox/organizations/
Interestingly Firefox Focus uses WebKit (/Blink?), since that's what Android's webview provides. Firefox for Android should get the improvements around version 58 or 59.
Also good to note, for people planning to stick with an older Firefox for as long as they can: Firefox 52 is an Extended Support Release, and as such will actually be actively supported until June next year. This will give WebExtensions some extra time to mature for more use cases: https://www.mozilla.org/en-US/firefox/organizations/