I’m not really a fan of this kind of system if it gets implemented. Sure, we can cash out at a certain multiplier, but it still depends on the original combined odds. I’m guessing we’re talking about parlay bets here since there's a x2, x3, or x4 I see. Let’s say your parlay is at x10, and you decide to cash out at x3, and the bookies actually give you that, even if your bet is 99% likely to win. Would you honestly be okay with that? You can’t really complain since it’s their odds, and they can always justify it however they want.
Most of the user that will use this feature doesn’t watch the game or doesn’t care about the actual winning condition of the game since their goal is to cashout at certain profit amount.
These users are those staking an amount which they can’t afford to lose or huge amount which a certain profit is already good enough than risk their stake more for an additional profit.
For me, I will only use this feature if I’m not confident on the remaining match and I don’t have time to watch the game.