Do you keep your shoulder blades together for push-ups

I know you keep them together for bench press, and for years now I would do standard push-ups with my shoulder blades together.

What really brought the question up was doing ring push-ups. Should I be keeping them together, or try to use a bit more range of motion and let them come apart. The biggest reason I read for keeping the shoulderblades together for a bench press is to provide a more stable platform to press from. Obviously you aren't doing this with either type of push-ups. The second reason I see is to shorten the range of motion so that you can lift heavier. Well, in my opinion more range of motion sounds like a good thing in push-ups.

Am I wrong in this line of thinking? Is there some injury prevention involved in this for push-ups?

Thanks for any answers in advance.