Hello, just to make a feedback : it didn't work. And I want to share my opinion, because it is very frustrating.
I have tried a
batocera-save-overlaycommand but couldn't find the script location (and the command does not work).
There is indeed the
/recalbox/scripts/recalbox-save-overlay.sh script : that worked and allowed to override the
rendering-defaults.yml file after reboot, but when I launch a game, I have something like
configuration core loaded and the shader I want is not loaded.
In short, it's tiring. No one has a real solution to this problem. I have tried, for myself, but also for people like me, and I try to report, but I am not a developer, I can't do better.
There is indeed the Batocera Menu, where we have the choice between Shaders:
None/Auto/Retro/Scanlines/Enhanced, but we would also like to have the rest (a world !) of libretro scanlines choice.
This is disappointing, yet it is a request made by many members here, and a necessary feature in the retro-gamers community easily configurable in retropie and recalbox. Why to ignore us like if this request doesn't exist?!