I have three comments, the first is about the boning. The purpose of the boning is so you can observe your baby and also to provide ventilation so the baby gets some fresh air under the cover and can see you when they are old enough to want to establish eye contact. It can prevent them from always trying to bat the edges of the cover away (always at an opportune moment, of course).

Second, either the velcro or d-loop strap closures work but the d-loop strap should already be closed and just adjusted after lifting the strap over your neck. Velcro works especially well if the strap is single and wraps all the way around the neck to fasten over the right shoulder. Put the rough side on the cover and you can place more than one smooth strips on the strap, making it adjustable if necessary.

The last comment is that adding a pocket at the base and/or some fabric/trim that can be used to weigh down the bottom or even just the corners can help to keep the blanket from being blown/batted off of the baby. I like the addition of flannel, terry cloth, a t-shirt knit, or diaper cloth at the base or corners on the inside of the cover. this gives both weight and also a nice drying area should the need arise. The pocket can hold nursing pads and/or burp cloth and hand sanitizer wipes, especially with the addition of a velcro flap these items can be stored making mobility easier. Each of my children was different and our routines were different but after I had more than one child, the ability to nurse while moving around the house, although not ideal, was essential.