Of course :) As you said, that's our copy for testing and work. That permissions are for us to work, not our client OTRS side!

I emphasize it because you WILL forget to put them back (voice of experience). You’re much better off working in the same environment with the same permissions as the production system. Saves all kinds of debugging grief, and reduces the opportunities to say “just chmod 777 and let’s get on with it.”