What does the maximum win actually cap?
Deciding how long to keep a session going depends on a bonus round that nobody can time. How often the Free Spins arrive is not known in advance. The result of one session is random, whatever the RTP says, and a long run of base game spins can end with nothing back. Each spin in Bigger Bass Splash is decided on its own.
Checking the RTP version comes before the first spin. Which version Bigger Bass Splash runs is shown only in the game rules. Open those rules before you stake, and do not assume a version from the game name or the series title.
Weighing the maximum win means reading it as a ceiling, not a target. The top prize of Bigger Bass Splash is reached very rarely, and no session can be planned around it. The figure marks the most the game can pay per bet, nothing more, and it says nothing about when that win will land.