Certainly at least AmigaOS 2.0+ can boot from any floppy drive. I can't remember if KS 1.2/1.3 allowed this, IIRC not.
Anyhow, even if you can start the loading from df1: the game/demo might still use direct hardware banging to do further disk reading. If this happens the demo/game will try to load from df0: and if the drive is not present or has no disk, the demo/game loading will fail.
AmigaOS legal games/demos will load from other disk drives ok.
