Would like to bring Brave to Gentoo, but how to "install" the result of a build

I am investigating how to create a package (ebuild) in Gentoo Linux.

I was able to build brave from git https://github.com/brave/brave-browser.git following the instructions at https://github.com/brave/brave-browser/wiki . As per this wiki, I was able to run brave directly from the top level directory of the git repo workspace using: npm -C start Release

Now I want to be able to “install” this version somewhere so I can use the git workspace to build newer versions without interfering with the result of my successful build. I couldn’t find any info on this on the wiki page.

In case it is relevant, here is what I built:

commit 8af00a618b581da0792efeb2f0773bffac3cece3 (HEAD -> master, origin/master, origin/HEAD)
Author: brave-builds devops@brave.com
Date: Sat Jun 29 12:00:12 2019 +0000

Bump version (0.69.17)