If the demanded outcome is to press the button and end up in your desktop/wm without a login of any form, then why use a DM at all and not use nodm, a properly configured .xinitrc?
I also found this workaround for debian, I think it can be configured for obarun as well.
https://www.enricozini.org/blog/2008/tips/lightweight-autologin/
The problems I see with this is that if you do this to the system then some upgrade that may break something in X or DE will end up in nowhere-land for all tty, including the emergency tty12 where root can't even login. Once X starts then other ttys are available to work, so maybe not as big of a problem.