I know that LXDM might be more directly related to LXDE, but it seems
that LightDM is a reasonable, well maintained alternative.
Do you think it could be an option to use LightDM instead of LXDM for
the LXDE spin?
I am using LXDE with the Adwaita cursor theme. This theme provides a
busy cursor, but it's never shown on application startup, even if it
takes a few seconds.
StartupNotify is set to True in the relevant desktop files.
Do you experience the same behaviour?