I'm a huge fan of sand in the run. In my coops, as well. I'm very sensitive to smells. There's nothing smellier than accumulated chicken poop. Sand allows me to scoop the poop, eliminating all together the smell of chicken poop.
You want to know what else scooping poop eliminates? Flies. Zero fly problem when you scoop the poop every day. Healthier chickens, too. They aren't wading around in accumulated poop which gives their immune systems a big break.
I buy construction sand at the local gravel yard for about $15 a half yard which I haul home in my light pickup. A yard of sand will do a 400 sq.ft. run.
I definitely think sand is a good option from my experience. I have high perches and the chickens don’t get bumblefoot now that I have a sand floor. Depending on the type of sand the chickens can dust bathe in it as well. It also drains really well depending on what’s underneath it so mold doesn’t grow when the chickens spill water.
My only recommendation would be make sure the sand isn’t dusty, as my chickens constantly flick it into water and they can inhale the dust when they’re scratching. I’m not really sure how you would be able to check that but maybe something with larger grains? Aside from that I don’t think there would be many bad choices for sand. This is only from my personal experience though.
Just adding after looking again at the image, if it can be used for sandboxes where kids would be digging it up and presumably not inhaling much, it would probably be a good choice.