Madoka's use of the grav-con helps to keep them both more grounded, and helps Tidus to pick himself up, no matter the threat of the wind returning. Romeo asking about making him invisible, and what would be better?

"What about you three?" What would be too hard on Romeo? Easiest? "I don't mind being a target-- but you three, you try knocking them down! Use snowballs! Let them come for me, I'll defend myself! Okay? Madoka," and he looks at her as he says her name. "You can jump with the grav-con--but be careful if you do, alright? Don't get blown into the cage!"

He'd shown her how to jump in theory, but just for a while, a simple flip of the switch in the other direction. But it hadn't been more important than keeping to the ground. ...other than being fun when it was safe...