STABLE version -- 5.0.1002.354

[sefiqin]

You can try my bookmarklet: https://gist.github.com/Hth4nh/b892045068a862629a1ab512a8f51eee
Triple-click the 4th line, then drag & drop it to your bookmark bar
When you need to install an extension, you just need to visit the extension's link (for example), then click the bookmarklet and you're done.

You can't get far on crutches. A new version is needed, and its release is very delayed.