Treat the ceiling as a ceiling, not a plan
Torpedo Symbols land when they land, and no schedule tells you how often the feature arrives. Each session deals fresh random results, so the return figure describes a very long run of spins, not your next twenty minutes. A quiet hour proves nothing about the next one.
Two versions of the maths can sit behind the same screen, and the game rules name which one this copy runs. Look there before you weigh the published return against your budget, because the figure moves depending on the configuration.
The top prize is a ceiling, not an expectation. It waits on an extreme run of nudges and multipliers and turns up very rarely indeed, so treat any single session as a normal one and stake accordingly.