One trick is to turn the volume way up, and see if you can hear it "backing" as you make another deposit into the casino, if so, it is probably nearly ready for the streak. Provided you are not compelled to collect any of the prizes, you should be able to force it. You could also try turning down a few of the top jackpots, and then wait until it just spins straight in, as this should repeat until the casino is empty.

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Easy, you can get a USB Refill key reader, and this allows access to the operator options, including when the last jackpot was won, and whether by KK or not. With the deluxe version, you can see the current payout percentage and the target percentage, and how much money is left in the casino, expressed as how far short of "full" the casino is.
Unfortunately, refill keys are specific to individual casino groups, and so far I only have one for Purple Lounge, but it works a treat on the video slots as well

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