Deciding before the first spin on Sword of Ares
Deciding how much to stake is yours, but how often the bonus round comes is not known in advance. The RTP does not tell you how many spins pass before free spins start, and every spin is random. The result of one session is random too, whatever the RTP. Expect uneven results, since the volatility is high.
Checking the RTP version you are playing is worth a moment before the first spin. The version this lobby runs is shown only in the game rules. Read that section before you deposit, so you know which of the two versions applies to your play.
Weighing the top prize against your budget comes first. The maximum win is a ceiling, reached very rarely, and it does not describe what a typical session pays. Keep each stake within what you can afford to lose, and read the top prize as a limit, not a target.