dvrgrl38- any chance you could show a pic with how the prefold looks laying inside the cover and how you folded it? I tried this with my preemie prefolds (Bummis) and couldn't get it to work in my bummis original cover as the prefold was so narrow and long. They are not the wide cut prefolds. I was going to get some superbrites as well, but not sure how useful they will be, so would be really helpful to see how you made it work . Just didn't realize the cut of the prefolds before ordering them.
Only cover it has worked in so far is the Nana's Bottoms preemie as they are trimmer in the crotch than the other brands I have tried (much nicer!). So I have ordered lots of these as we were planning to do a lot of trifolding in that stage as well!