I just tried this strategy last night at home. Now mind you, I'm not a great player at all. My previous GC score was about 98 million but I have not even been close to that lately and are usually in the 10-20 million range on most games. Playing only PD3 I had games in the 40-50 million range and did get a new GC score at 109 million (and that was with a horrible last ball).
This strategy also seemed more 'fun' last night as it was nice to challenge myself to actually finish the mode which I was able to do a couple of times.