To avoid Starship exploding, SpaceX did this...

There may be two possibilities for an explosion. At liftoff and at staging. Let's take the each one in turn. At liftoff, if the water doesn't come out fast enough, it may flash to steam at a time that may be inconvenient. That would be when it is still coming out. If the rocket exhaust hits the metal first, the water underneath could flash to steam and build up suddenly in an explosion. If the water coming up is sufficient, then the water won't flash to steam inside the metal table, and there won't be a buildup of pressure, and no explosion. That can't be tested until it is launched at full power. The tests thus far have been 50% power. What happens at 100% power? We'll know when it happens.

Something similar could happen with the hot staging. If there's too much pressure buildup too soon, it could cause an explosion. The staging ring should relieve enough pressure so that an explosion won't occur, but that hasn't been tested yet. We'll know the answer once the rocket is launched the next time.

The most potential for a disaster would be at launch. It has a full load of fuel onboard. If that explodes, it won't be pretty.