When we had our soft floor, we carried a plastic grass rake to get all the sticks and twigs.
Then laid green 90% shade cloth down, this also helped with sand and crap not sticking as much to the vinyl floor area, which made it easier to clean when folding up at pack up time.
For the legs of the double bunks I had pieces of carpet that protected them from pushing hard against the floor, same for the bottom of the ladder.
This worked very well with three young kids at the time.
We never had a hole or a cut in the floor the time we had it.