Wow, you're right, Gary. That was a great video. And it re-emphasized my desire to get a MIG...I wouldn't want to try those inside welds he performed, using my stick welder.
So, I'm assuming that when everyone was talking about modifications to allow 45 degree angles, they were referring to how he notched the side pieces out? The reason I restarted this thread was because, yes, I'd like to buy a SM, but if there's a modification that substantially increases its usability, I'd prefer to go that route, even if it requires fabbing up the pieces myself.