transition out of swaddle?

So my baby rolled from tummy to back the other week but hasn't done it again. I bought some halo sleep sacks to transition him to no swaddle.. anyone like them? It says 3-6 months on the size so I'm assuming I can use it as a wearable blanket for the winter. But says to stop swaddling when he starts showing signs of rolling and breaking out of the swaddle... so does that mean I can't use it then? I'm so confused on what's safe then. . Would I just swaddle him with his arms out? Or does his feet have to not be covered anymore? Confused mama over here...