Accept that the next spin is random
Each spin lands symbols across the 5x3 grid, and the 15 paylines decide what pays. Whether temple Scatter symbols land on reels 1, 3 and 5 is random, so the bonus round arrives at an unknown moment. How often that happens cannot be known in advance, and earlier spins say nothing about the next one. The result of one session stays random whatever the RTP.
Symbols settle on the reels under one RTP version, and the version your session runs is shown only in the game rules. Olympus and Hades each carry their own RTP set, so the mode you pick on the Choose Volatility screen decides which set applies.
During free spins, an expanding WILD locks in place with a multiplier of 2x to 100x, which is the route to the largest wins. The maximum win is a ceiling reached very rarely, and no session can be planned around it.