alt Hacker NewsAnd if you want any concurrency at all, you need 1 runner registration per concurrent job. And each runner needs its own user. And each runner requires a full and separate copy of the runner software, which is large (hundreds of megs) and self-updates.
You don't need your own user.
The rest is correct. (Though you can hardlink the installation.) And you can disable self-update, though it does it by default.