It takes weeks after I stop smoking weed for me to start remembering my dreams again. I don't doubt that there are other effects on sleep from acute smoking around bed time. But for me, the loss of REM sleep is definitely mainly a function of cannabanoid tolerance.

After many years of on and off heavy smoking, I would say that the best best practice is actually not smoking weed every day. I think there are some amazing benefits to weed, but for me they all but disappear with enough tolerance.