Mardi Gras: Dining at Cucina or Chibang

We have an upcoming sailing on Mardi Gras and I do not understand the dining for the Chibang and Cucina dinner option. If we have early dining time , can we still eat at either of these restaurants for free one time? Or is that option only for the Anytime dining? How long is the wait typically for Anytime on a fully booked cruise. We have two late teen boys so not sure if we would better off with the Anytime dining or stick to early dining so we’re guaranteed to eat before 8pm. Thanks in advance!