I've got my medical marijuana card and smoke a lot and love it! But from my experience, weed hinders your dreaming progress a lot. I'm not saying you can't dream or LD when smoking but it just makes it a lot harder to do. It's kind of like if two people are racing to get to the other side of a pool. One is running beside the pool and one is trying to run in the water. Both are going to get to the other side but the one in the water is going to take a lot longer. So if you want to make progress faster you need to be sober when going to bed. Also, if you are a heavy smoker when you stop smoking dreams come back with a vengeance. Every time I take a break from it, I can remember 3-5 dreams in great detail and length the very first night stoping. But if I go to bed high I'm lucky if I even remember just one.