You’re correct however the volatility should be the one that you are aiming if you want to compete with multiplier contest with low minimum bet since you can get huge multiplier if you manage to experience lucky hit.
Most of high RTP has low volatility which is only good if you are competing on slot multiplier contes5 with high minimum bet so that you can easily hit a medium high multiplier even on small number of spin.
Yep, slots with lower volatility could be useful for such contests, but then again, as I said earlier, that's only possible if you are allowed to choose any slot of your choice, from any provider, but most of such contests will have limitations on such things. They will either tell you which games you can use, or you can only use games from a specific provider, and some providers usually only have games with high volatility, such as Pragmatic. Most of their games have very high volatility, and it's very difficult for you to hit high multipliers with their slots.
If the contest gives you the free will to choose your games, and they only care about the multipliers you get while playing on their platform, then it can be more fun because you can try different games from different providers to see if your luck works in any of them, and then you might stand a chance of winning a prize because you now have a broader game menu to choose from.