I believe this is a bug in the current DAZ version. Previously Daz saved render settings. It's been annoying me as well.

One option is the Render Setup Storage plugin:

www.nightstone.com/~guandalug/DAZFreebies/plugins.php

Which is useful even without the bug if you're changing a lot of stuff in the Render Settings. If all you're changing is the render target, though, you're probably better off waiting for the next stable Daz version (assuming that's not a contradiction in terms....)