Ideas
This Get Together top for masculine framed sims (ymTop_EP02SweaterShirtCollared, if my sims 4 studio digging was successful?) looks okay on feminine framed sims from the front, but has this weird v-shaped distortion on the back. I've attached pictures showing the item on both a feminine and masculine framed sim to show the difference.
(honestly a HUGE number of masculine tops in the game have this issue when worn on feminine frames, after looking through the content of the first few EPs I would guess it's an issue on about half of them? Maybe more depending on how picky you are. It's less noticeable when there aren't any really patterned swatches, of course, but there's often some weirdness going on at the hem right along the spine. and as my next post will demonstrate, it's not jsut the early EPs that have this issue!)