What was the purpose of the deco bottles? You are working with rules of 6ths and no deco according to the standards.
Besides, it's not like you are going to tote those around on a cave dive.
It was mostly just for drilling with on buoyancy while in the cavern. Dropping at the entrance, picking up at the exit, managing buoyancy along the way - not everyone in the class had any tech training in wrecks. For those who did, this was old hat, for the newbies it was just another twist.