I thought I would post here the fix i used to get Spyro 2 to work on Batocera. As such the game runs fine until you go through a portal (like to Idol Springs) and the game gets stuck (mednafen) or crashes (rearmed). This might be due to a bad dump or something to do with the weird copy protection it is supposed to have, I don’t know :).
The fix, after some googling on other forums, appears to be to copy the .sbi from http://redump.org/disc/1182/ and to put it in the same folder with .bin/.cue files for the game. I think the .sbi file has to have the exact same name as the game files (for me it was by default). I don’t know what exactly the file contains, I’m sure someone more knowledgeable can chime in.
After the file is in the folder, just restart the game and it should work for both emulators. I only tried it for the Summer Forrest area.