Splash screen and auto_start script has a gap

I currently have dietpi loaded on my rasp pi 4
and have my splash screen setup but when the splash screen finishes, it shows for few seconds that code running where it loggs in and runs the autostart script,

how to omit this logging
how to gracefully transit between splash screen and my application,

info:
my autostart script does 3 things

  1. starts the Xserver
  2. starts openbox
  3. and starts my application installed by dpkg.