Agree on the ridge between the machine bed and the plate. It can twist a seam.
Because I clean my machine a LOT I don't want to put tape over the seam. So what I do is this ....
I can feel a seam coming up (even if there is only a seam on the bottom) with my fingers as I feed the seam into the machine. When I feel one coming up, I slightly lift the piece I am feeding, and if necessary will reach under and flip the seam. I very rarely get a twisted seam.