It's not possible on Pseudo Saturn, and I don't plan to add such feature on Pseudo Saturn Kai.Is it possible to configure Pseudo Saturn or PS Kai to behave like a stock Saturn (no splash screens/menus etc.) on boot when booting retail discs?
Details : my vision for Pseudo Saturn is to make it more than "a hack that loads CD-R copies of original games". So far I added backup memory cartridge feature to it (*) and next release will allow usage of cheat codes. Theses two features can be used on both CD-R and original CDs.
I did my best to remove usage of menus regarding backup memory cartridge feature (so far Pseudo Saturn Kai was prompting if it should be enabled or not, but next release will decide that automatically), but this is not possible to do that for cheat codes since user may want to choose which cheat to enable.
Additionally, why aren't you using a modchip your Saturn ? This can load both original and CD-R games silently as on a stock Saturn hence may be more suitable to your needs.
(*) This is available for Gamer's Cartridge only. I don't plan to add this for flash ROM based solutions such as Action Replay cartridges.