I realize most people are going to see this as a trivial gripe, and perhaps it is, but I feel someone ought to bring it up.
It seems that someone, at some point, arbitrarily (or perhaps accidentally) decided to rework the cores somehow, so that when you save a core override or remap, the folder begins with ‘Beetle’ instead of ‘Mednafen.’ Besides the obvious complaint that all of the other cores that I am aware of are named exactly after the core (and not the ‘nickname’), this breaks overrides and remaps that users have been using for a long time.
It started with PSX and PSX HW, and more and more of the cores are adopting this. But not all of them! The PC-FX core, for example, is still rightly using ‘Mednafen PC-FX’ as the folder.
In my opinion, the core override and remap folder names should NEVER change, unless the actual core name changes, too. If I am forced in the future, for example, to download 'beetle_saturn_libretro.dll, that’s fine, and it’s my own dumb fault for not catching that when the override/remap files no longer work. But otherwise, what was the point of the change? Any time a name change like this occurs, it’s an inconvenience to everyone that uses those cores, and has to figure out on their own why things are broken.