Since the main idea of slot multiplier contest is to get the highest multiplier, maybe some people are not willing to force themselves to chase high multiplier because they may need to spend much money for it. How if make a change for the contest to something like closest multiplier contest? For example, you set a specific multipler (lets say 123.45x) so anyone with the closest multiplier win the contest. Or maybe change the rules of the current contest, make it daily sumbission so there will be 7 multipliers max and those who have highest total multiplier wins. Of course some changes also needed to make attractive, such as lower minimum bet and maybe higher prizepool since players will need to play every single day to collect good multipliers.
Daily contests will be a very labor-intensive process, you need a separate person who will do this, and I think that not everyone plays slots every day, which will also not attract so many players in this case.
I personally did not participate in this contest because I don't really like slots, but it seems to me that your proposal for a daily contest will have difficulties in implementation. A week's time is much better for the contest. But your idea of "hitting the target" could be introduced as a criterion for an additional prize. In general, as I understand it, it is necessary to attract more participants, so the prizes awarded according to different criteria could be of interest to more potential gamblers.
It seems to me that nothing attracts as much as something free, so it would be possible to make some kind of prediction contest with a prize of several free spins, this would attract new players from the forum, and then who knows, maybe they could become regular players of Casinopunkz in the future.
I dont know, maybe even just add a prediction contest to the current contest with the largest multiplier, what exactly the winning multiplier will be, the closest prediction will receive several free spins.