It's OK for quick and dirty, but I by far prefer cutting strips, gluing them up , trimming smooth. The iron on doesn't improve the strength of a shelf, a good hardwood strip does. Glue thoroughly, I put 2 coats on the ply edge because it really soaks in. Clamp the strips in place same as you would glue up a panel. If I'm going for strength, the strip will be about 3/4 inch wide.
With iron on strips, you still have to trim the strips even with the ply. If the strips are solidly attached, then trimming can be done with a sharp block plane, or you can purchase a trimmer. I personally only have disasters trying to use a chisel or another blade. You can use a trim router as well. And as mentioned, I prefer to use a slightly rounded stick rather than a roller. Never tried applying glue first...I'd want to test that out on scrap first.
Man, you sure got that question answered thoroughly.
Oh yes, welcome to the Forum.
The more I do, the less I accomplish.