AFAIK the only SNES games which can actually detect lockout chip being disabled are the many SA-1 games (I don't really know details of these, other than the lockout is on die and it can be switched regions by tying a pin high or low), and the two(three if you count regions) (star ocean(J) and street fighter zero 2(J)/alpha 2(US)) which use the S-DD1, which has the lockout chip embedded on-die along with a pin, pulled high or low, to switch between pal and ntsc region. If the lockout stream is detected as failed, the chip disables the decompression engine and passes compressed data directly in during dma rather than decompressing the stream.
Ah, that might explain why my japanese Star Ocean cartridge only shows garbage when I try to play it on my PAL SNES... I already wrote it off as "broken", but hey, for 400 yen I just couldn't resist buying it ;-)
Sooooo... is there any way to "fix" it so that it works on PAL consoles? I think if I knew which pin selects PAL/NTSC I could try and reroute it...