It's unlikely there is any slot machine in Nevada "at the legal limit." Every gaming device must be set to theoretically pay out a minimum of 75% of wagers -- i.e. the maximum it may keep (or "hold") is 25%. This is, of course, a theoretical number, on any given day a particular machine may hold more, or it may have negative hold -- just like if you flipped a coin enough times, occasionally you'd get long streaks of heads or of tails, even though theoretically it should be 50/50.
In reality slot machines are typically configured to hold between 6 and 15%. A slot machine holding 25% would be an awful experience and simply not get repeat play. Slot manufacturers prepare each game with a range of options that the casino can choose from, but none of them would deliberately ruin their own game by offering a 25% hold option on a slot machine.
Nevada Gaming Control Act Regulation 14: 14.040 Minimum standards for gaming devices. 1. All gaming devices must: (a) Theoretically pay out a mathematically demonstrable percentage of all amounts wagered, which must not be less than 75 percent for each wager available for play on the device.
https://gaming.nv.gov/modules/showdocument.aspx?documentid=1...