If you press shield after you start side-special but before you actually hit the ball, you'll go into free fall and the ball will just bounce in front of you. You can then hit it with any move you want!
Different moves will give you different angles and speeds, but my 5 most used angles for edge-guarding are:
If they recover high like you mention, you can side-special toward stage and then forward-tilt back toward the ledge. This will result in hitting the ball with your back foot and sending it with a nice arc to catch anything high:
For a fast ball straight ahead, you can do a forward-tilt in front of you:
This is probably my most used edge-guard. It's both simple and covers most recoveries.
Cancel the side-special on the ledge side, and then immediately input a single jab:
The issue with the other low technique is that it goes a little far from the stage. If you have someone who's recovering closer to the stage, they'll be safe from it. At this point, I'd go off stage and look for a down-air spike, but maybe the opponent has a dangerous recovery for you or you prefer the stage. In that case, this one's for you!
You'll have to be pretty close to the ledge, since you'll be sending the ball straight down. Cancel side-special toward the ledge and then immediately do a short-hop down-air (this can be buffered easily by holding jump, attack and down on the control stick right after you go into free fall from cancelling the side-special):
This one will give you almost the same angle and speed as a simple jab, but if you're feeling a little spicy and you want to impress people, you can go for a back hit of forward air.
Cancel side-special toward the ledge, then immediately turn around and short-hop fast-fall a forward-air:
If this lands, it'll pop the opponent up perfectly for a run-off down-air to maximize the spiciness. You can see me instinctively beginning to run off-stage for one in the above gif.
There are of course a bunch more possibilities, but these are the moves I've found to be the easiest and most useful for covering recovery options.
For all possible moves and their trajectories, I'd invite you to look at these absolutely incredible graphs put together by Ashlynn Zlicious (@violightning).