I'm not sure how high off of the ground that cage is. I elevated my brooder in the coop and my grow-out coop and made the floor 1/2" hardware cloth. It is elevated enough that I can rake the poop out from underneath. When the chicks get to be about 12 to 15 weeks old the poop gets big enough that it stops falling through. You then have to clean it.
In colder weather I put a piece of plywood in a section of the brooder for the chicks to sleep on. That stops drafts from underneath. To clean that, I just tilt it and scrape the poop off. With no bedding and the poop falling through it stays bone dry even if water spills. I consider it extremely healthy for them since it stays dry.
The way hardware cloth and wire mesh is made, it can have sharp pips that can slice open their feet. That can come from the welding process or the galvanizing. Not all mesh wire has this. From the ones I've seen that do have it the pips are on one side, due to the manufacturing process. When assembling my brooder or grow-out coop I checked out the wire mesh by carefully rubbing my hand along the sides. I put the pips pointy side down so the chicks are not standing on them. If you install it with the pips up they can tear their feet up on them.
