I work with acrylics exclusively, due to hubby's allergies, and I've never blocked anything. I've made baby blankets, hats, scarves, sweaters, afghans, etc.........and haven't blocked a single one.
Once you've finished your blanket (which is coming along beautifully btw), you could do something to even things out or just decided to leave it the way it is. Sometimes my projects curl/turn up while I'm working on them and then smooth out after bind-off. You never know how things will turn out.
My suggestion is to take a look at it after you've finished. Lay it out on your bed or other large flat surface to see how it's draping. Then decide what you want to do.