Our Swienty floors came with self-tapping screws for attaching the mesh.
There are at least two styles of floor/entrance. The two we have are both almost flat-fronted - nothing is proud of, or sticks out from, the front of the hive.
One has a ramp built into the polystyrene, the other just has the entrance on the outer face. The latter is, I think, 2 bee spaces high, the former is only one bee space at its shallowest. (If I've got time, I'll try to check tomorrow)
We've used strips of frame bottom bar to reduce the width of the shallower entrance, and have also reduced the other to only one bee space in height.