Ness' tech chasing situation is pretty bad but he does have some options.
For starters, the dash grabs can work if you predict that your opponent is going to roll but is pretty risky as misjudging what your opponent will do and using your grab will give you lots of end lag.
One thing that I like doing is using f-tilt as it's very quick and covers a decent amount of ground but doesn't really open up for any follow-ups on low percent. You could use f-smash if you're absolutely sure it will hit but it's very risky and if you're in a situation where you could f-smash then you should just f-tilt in case you miss.
Dash attack is okay, no pun intended...but for real if you're opponent is close to the ledge/is ledge rolling then dash attack is pretty safe. Although make sure to go for the third hit as it is the strongest and sends your opponents upward giving some possible follow-ups like fair or uair.
Lastly, some people try to go for the yo-yo glitch (which in my opinion is probably the best way to get the yo-yo glitch) but keep in mind that it's very easy to mess up and if your opponent knows what you're trying to do then they can easily work around it/get rid of the hitbox.
