@ManueB I can add that bumblefoot, from what I have read and from others experience or suspicions is that common causes are repeated landings on a hard surface, like a concrete coop floor (I picture it as the foot hitting a tiny pebble or rock, but it doesn’t give because the surface beneath is hard so the flesh is injured, it but it might be a repeated bruising that goes bad internally). Or something sharp cutting or puncturing the foot like what you are fearing, sharp edges, but it can be splinters or thorns (wild roses or brambles in the case of @Kris5902). Do you see your birds using the ramp or jumping right off?
Some people use a series of small steps instead, as you suggest. I’d use at least two with the height you have.
If you are concerned about the screws on the ramp steps, since they aren’t countersunk deeply, maybe that could be a cause. Do the screws go through all the wood and stick out the other side? If not, remove them, and screw them back in to the steps from the back side. That way there’ll be no heads on the upper side.
Before you do that though, either sand and smooth all the corner edges, or get wood lengths that are easier to smooth. Young tree branches might work (the smooth lengths between branching), or if you can buy a split dowel, that would be great because it’s a half-round shape and will sit flush on the ramp.
The heart was for Rosie and you and your mom. I’m going to put out there that Grandma does it because of separation and change anxiety. Not excusing it by itself, but her dementia makes her a toddler this way. The hard thing is our elders are armed with bigger guns than toddlers have and can do more damage.
I don't know when they move up to the roost...but eventually they do. Weirdo chickens.
