Hey everybody! I use Vulcan for all my cores, but recently Kronos have gotten me curious - and like to play Saturn games in high res. 
Is there a way not to have to change driver manually every time (and restart Retroarch)? Thanks!
Unfortunately not. There’s a bounty open for it, but currently you need to change it each time or have a parallel installation.
You could use an additional config file in combination with a windows shortcut and the “appendconfig” command.
This is the content of the cfg file (retroarch_gl.cfg):
video_driver = "gl"
You can also add a OpenGL default shader:
video_shader = ":\shaders\your_shader_preset.glslp"
This is the target of the shortcut file:
D:\path\to\RetroArch\retroarch.exe --appendconfig "retroarch_gl.cfg".
With this solution, you can still use your normal retroarch.cfg and there is no need to have a parallel installation.
yeah, this is exactly what I do on my Windows machine that I use for testing a bunch of different video drivers. It works well, though the setup can get a bit hairy, depending on how many things you want to switch among
I do GL, d3d9, d3d11 and gl_core, with 32-bit and 64-bit of each, and they all share the same config but launch with different drivers and different menus with paths to different bundles of cores as needed.