Now, how exactly can you install the latest Metamask extention:
- Go to Metamask GitHub releases page and download the latest one corresponding to your operating system
- Create a directory on your computer and extract the zip content un this new directory
- In Brave, go to brave://extensions and enable "developer mode"
- Now simply drag and drop the created directory with Metamask new release in the extension panel, and it will be installed as an "unpacked" extension.
As for updating the extension, fetch the new release from Metamask Github Releases, clean the previously created extension directory and extract the new version into it. When it's done, click the extension reload icon ⭮ in brave://extensions
Enjoy your bleeding edge extension!