That's a very clean set up you've got there and beautiful birds, they look like cross Seramas to me, they don't need dirt to scratch around in, they like it but it is not essential for their health, giving them a tray of sand with perhaps a bit of DE mixed in should be fine for a dust bath, I have my birds in a run with pebbles which is far more hygienic than dirt and easier to hose down, I also have lattice panelling with no wire, provided the birds are locked up securely overnight I see no problem in this.