The requirements for endings have changed.
I got Ending 2 by beating the Floor 100 boss with 20-30 orgasms, so that part seems correct.
But afterwards I got Ending 4 when defeating the final boss, even though I barely had any orgasms. I was "supposed" to get Ending 3, but didn't.
Defeated the final boss on Floor 260, with the red New Ruler title, as a virgin (used the OP instawin virginity card).
So I did some research, and it looks like the new requirements are this:
Ending 1: Beat Floor 100 for the first time. Would need new save if you already have Ending 2.
Ending 2: Beat Floor 100 for the first time while climaxing 20-30 times. Would need new save if you already have Ending 1.
(DLC) Ending 3: Beat True Final Boss using at least one key without picking any red options, New Ruler counts as a red option.
(DLC) Ending 4: Beat True Final Boss using at least one key while picking red options, you need to pick New Ruler before starting a run.
Red options include: Picking New Ruler and killing NPCs to get crimson flowers, but also things like releasing the prince from prison. I can confirm that these ending requirements seem more accurate than what's been posted earlier in the thread.