Ooh, very interesting. I do the V at the back, and it deffo rolls right at the deepest part. A lot. I can certainly do your cheat, but in the future, that means that if I stick with the V at the back, I need to do a shallower one to avoid the roll? Another skirt I did was straight across the back, and it rolled, though maybe not as much. That one had a yoke, too. I can't seem to win.
Also, if you do a zigzag, how do you avoid stitches popping? I don't have a serger, so do a very long and, I guess narrow? (a la Jalie, my width is set to 1mm and length to 3mm, 'normal' is 3mm x 1.5mm) zigzag, and I am constantly blowing stitches as I pull the dress on and off, especially along the horizontalish hems. I did a cheaters princess line- straight across the top of the breasts on the last one, and that seems to be where I'm losing the most stitches. I thought it was the skirt, but I ended up attaching that with my machines super-stretch stitch and that seems to be holding. That latter is H E double hockey sticks to rip out though, so I'd like to avoid using it in the future.....
Sorry Saje, not at all trying to hijack, you and I are having similar issues at the same time. Hopefully your skirts aren't popping stitches!