As a user of super fun and cool jump boots, I occasionally find myself in spawn after it's covered in lava. Unfortunately, for most maps this means that when I jump, I end up in lava. I'm aware you can unequip the boots, but then you still have to wait the 20-30 seconds for the buff to wear off, and even then some people have issues with inventory space. It's not a huge issue, but I don't really see many downsides to increasing the height, provided the width or length isn't automatically increased as well.