Don't know if anyone's mentioned it. And don't feel like sifting through 120 pages to find it. But you can completely break the curse progression system quite easily. All you do is get the girl in question to the point where her two multiplier increasing (hard) positions are available. Then just click one and the other back and forth as quickly as you can. You can easily hit 80x multiplier or higher with a single stamina bar and get upwards of 20 million curse progress in like 30 seconds.
The reason I think it works is that the stamina cost has an internal CD, this isn't reset if you swap from one position to another super quickly. But swapping position forces a tick of curse progression and a multiplier increase without this internal CD. This lets you get multiple ticks per stamina drain and the aforementioned 80x+ modifier to just make you gain absolutely wild amounts of curse progress.
The reason I think it works is that the stamina cost has an internal CD, this isn't reset if you swap from one position to another super quickly. But swapping position forces a tick of curse progression and a multiplier increase without this internal CD. This lets you get multiple ticks per stamina drain and the aforementioned 80x+ modifier to just make you gain absolutely wild amounts of curse progress.