I have a lid for mine too, Tex, but haven't cut a hole yet. My concern is that you have to remove the Anova to get the lid off, unless you cut a gap in the back. That's probably what I'll do, and then just cover the gap with a little plastic wrap. Still better than covering the whole container!
Edit: I just went and did it! If you cut the shape of the bracket, there are no gaps, and you can give it a little twist to get it on/off over the unit!