Read the rules before your first Vampy Party spin
Each spin fills the 6x4 grid with new symbols, and no one can say in advance how often the bonus round will arrive. The result of one session is random, whatever the RTP version is. A long run of base game spins can pass without a single free spins trigger, and a short run can land two in a row.
Each spin stops the reels on new symbols. The RTP version in play is shown only in the game rules, so check them before the first spin and again whenever a new session starts. Read them before any stake is placed.
Symbols can chain through several tumbles in one spin, but the maximum win of Vampy Party is a ceiling reached very rarely. The cap is a limit on what the game can pay, not a target a session moves toward. A tumble chain can stack multipliers, yet no rule promises that a session nears the cap.