PSX core ignoring --save path?

I’m trying to make RetroArch (Windows x64 version v0.9.8, Mednafen PSX core) look for memory card files in a different location than the game ISOs (because I want them in my dropbox), but for some reason the command line parameter seems to be ignored completely, and memory card files getting created in the ISO path regardless. I’ve tried both -s and --save, with no difference.

Is there any way to make it work properly, or alternately a different command line parameter that works?

Mednafen PSX doesn’t interact with libretro’s SRAM interface, so -s or --save has no effect. It saves memory cards directly to system directory, which by default is the directory where the ROM is. The system directory is also where BIOS files should go.