Ok, I'm going to give a not full of shit answer.
You are doing exactly what DC training isn't about, which is overthinking something that is pretty damn simple and looking for some set in concrete answer.
The idea of a cruise that you have to appreciate is to give your body a chance to recover, adapt, and do whatever the fuck you want to meet that end. Cardio, light weights, stretching, absolutely nothing.
I'm going to patronize you now (just to make that clear), and you seem like a beginner or someone lacking experience or just plain commonsense, as trained people can figure this shit out pretty easy.