I have found that when I do binding, after I have initially sewed it on, I press it, just as I do with any seams, I am not sure if this is just me, but I have thought with this little bit extra of work that I would not necessarily need to cut it at 2 1/2, that it could be cut narrower. The next time I decide to sew up some coasters will definitely try the narrower, I do like how the narrow binding looks. The lady that I took my first quilting class with, said to cut the binding at 2 1/4, at the time I thought that was too narrow, but with pressing it would work, I think. Her words, I like to see a nice narrow binding framing the quilt, of course she hand sewed it to the back and that is where I would differ from her, yes I like the narrow look, but would rather machine sew it. I will watch this and see what others add.
Interesting and learning topic!