From this thread:
"I've been to Portal a few times but have yet to complete it.
You all know that in SOS you can complete modes if Flynn's is lit by shooting the scoop and it will award you the current running mode (for a lesser point value). So if you are having trouble with Gem or another mode you can just finish those that way. You can relight Fynn's with the right orbit during SOS too as many times as you want. Also in disc multiball during SOS you don't have to hit all the various lit shots, you can shoot the spinning disc in the center and each read of the switches in there (the optos) will award one of the lit shots. Sometimes that's easier than some of the lit shots, especially if your disc tends to kick the ball out fairly consistently to a safe place.
My best game so far is 187M. I'm pretty sure I had double scoring going when I started SOS and I had a decent amount of the modes completed and I got to Portal but didn't come very close to finishing it."