All S&W revolvers chambered for .45 ACP leave the factory with the ability to headspace without the use of moon clips. If one doesn't, something is wrong and it needs to be returned.

Just remember that without the moon clip, there is nothing for the extractor star to grap onto. You will have to remove the cases by hand.

Years ago, before the internet, I discussed the use of .45 Super with Ace Hindman. At the time, he was very leary of using it to its full potential in a 625. Given modern powders, I'm sure the 625 can handle it.