If you are counting rares, you will almost always grossly over-estimate the number of scrolls you've spent, due to pulling RNG rares (~1% chance per scroll), opposed to hitting the full counter in kage.

I did exact scroll counts on my f2p alt: I pulled 23 kage rares at 1010 scrolls used. The 10 draw from 1010 -> 1020 gave ay 4th.

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In 4.0, for kage treasure, you have zero chance to pull the super rare before 1000. After 1000, the first time you hit the full 60 counter, you'll get your super rare. (The counter can start before you reach 1k. For example if your last rare is at 980, and you draw no rares before 1040 from rng, you'll get your super.) If you are "unfortunate" enough to rng draw rares after 1k scrolls, your super would be delayed, as the counter reset to zero every time a rng rare is pulled.

There is also mostly negligible chance to RNG pull the super rare after you hit 1k scrolls. You'll almost certainly get your super from the 60 counter instead.