Confirm that the following disables gnome-keyring daemon completely:
Copy gnome-keyring-pkcs11.desktop, gnome-keyring-secrets.desktop and
gnome-keyring-ssh.desktop from /etc/xdg/autostart/ to
~/.config/autostart/ and add X-MATE-Autostart-enabled=false to each of
them.
There was some messing with this option circa januare 2015, as can be seen here
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=775189
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=775256
Still, it is not clear to me what for was created the option
"org.mate.session gnome-compat-startup". Please explain.
The default values for this option are "keyring" and "smproxy". It
does not work for "keyring", and no "smproxy" process seems to be
started by default. Thus, it seems that this option is not used for
anything. Maybe remove it completely?