Stuck in a long dry spell
Deciding how long to keep spinning depends on a question nobody can answer in advance: how often the bonus round arrives. That frequency is not known before you play, and the result of one session is random whatever the RTP. A short session can end well above or well below the RTP figure, so no single run shows what the game returns over time.
Choosing between RTP versions begins with the game rules, because they are the only place that shows which version this site runs. Read them before the first spin, not after. The three versions sit within 0.06 percentage points of each other, so the rules settle the question quickly.
Deciding how much to stake with the top prize in mind starts with one number: the maximum win is 20,000 times the bet. That figure is a ceiling, not an expectation. Players reach it very rarely, and no session can be planned around it.