Really? I thought this was an Egypt thing. If I recall correctly, during my (only ever) LB in Komodo there were more tanks and BCDs were switched among them. But might be as well that I confuse that with day dives...On a LoB there is one tank per diver - you set up your gear once and dive with the same tank the whole time...
How is is every topic of mine drifts toward tanks and gases . And I still do not know when to go . Pretty much choosing between June (more light, more chance for 4 dives), September and November (I guess no chance for 4 dives, run by my local school).