Scarification (cutting the coating of seeds) is to let water into the seed more easily for quicker germination. It's not necessary for most seeds. Doing so could cause rot or damage. It's used for seeds with a tough, thick coat that doesn't easily take in water.

Why would you want to do that for soft seeds? They don't need help to do what they do. Since these soft seeds are already permeable to water, abraiding them to allow water to get in seems a little senseless. Yes, it is well known that if you sand off the end of, say, a squash seed, it may germinate a little faster. I guess if that's a big advantage for you, then go for it. It isn't for most people. It does present risk, however.