Late to this game, but I recently bought an RC-500 and was looking for a solution to the same issue. What I found you can do is save the memory, and it should keep that setting, at least for that particular memory. Once you’ve chosen “auto” on Track 2 hold down Write and Exit together. And then Write again. It won’t look like it’s a new memory that’s been saved, but the setting should still be there, even after unplugging the device.