Aegir creates Drush aliases in
/var/aegir/example.org.alias.drushrc.php for the example.org
Here’s how to make those available to your non-aegir login as well.
It’s convenient to have these automatically available to non-Aegir users, and hijacking the full list of Aegir aliases is pretty straightforward with a few lines in /etc/drush/aliases.drushrc.php
Anyone using this will need permissions both to read DB creds for user aegir, and permissions to read/write to the shared www-data directories. They’ll then have access to everything aegir does – don’t do this if limiting developer accounts to specific site.