Zac hidden passive (Size and Hp): Does his E and ult hitbox increase?

When I started playing Zac I noticed he gets bigger with more hp (yeah, I know everyone knows it already). I thought it was just an "extra", for fun, but then realized bigger champions can block skillshots easier, are easier to be focused in teamfights, which is good for tanks. Anyway, my question is: In his E ability, Zac throws himself, and anyone he hits is knocked.. If he's bigger, will it be easier to hit E (larger range), or the hitbox will remain the same? Same for his ult, he knocks who he touches, if he's small, he has to be close to touch other champions, if he's bigger, then the ult would have more hit range, right?