The point of a dream sign is to RC on it, when it happens in waking life. So when we encounter it in a dream, we get an urge to RC and get lucid.

But RCing on dram signs is only one out of at least dozen other RCs and occasions to do them.

One of them you could adapt for your "gravity". IWL, think "if this was a dream, I would levitate up". Push off gently, without even using your muscles. Only your mind. And fully expect to lift off, because you are in a dream.

The most important part of any RC is awareness, and that we believe the RC will work, because we could be dreaming. Even if you think you know you are awake. Because that's what we all think - We are awake. Until we RC and realize we are in fact, dreaming.

Please check out the RC tutorial in this link Induction Methods and Techniques