it makes it easier to get the quilt under the machine but remember the quilt will not be any lighter in weight once you add on that 3rd section of batting because now you have a top, a backing, and the full width of batting.
so if your problem is only throat space this issue will be solved.
if your problem is moving fluidly with the full weight of the quilt - this method will only solve part of the problem because that last section will be very heavy to move and the second section might be and issue too.