Just a quick post showing the advantage of using a pressing roll. I’m assuming you know an ironing board and iron are as important as a sewing machine. I guess as much time is spent pressing seams as sewing them (even more perhaps?)
Two seams in a test piece of my ponte knit. No significant difference on the wrong side.
Same seams on the right side:
The seam on the right was pressed on a pressing roll, the left one flat on the ironing board. The imprint when ironed flat is visible in this fabric when ironed flat. This does not happen using a pressing roll. A roll could be made from a piece of round wood (broomstick) with a towel around it.