By the way, my whole Patreon account is marked as "adult" content from the very beginning, so the problem I mentioned above is less likely to happen. Not 0% but less likely to happen.
And as to DLsite, they check each item to be sold "before" each is on sell. If there is a problem including adult or not issue, they tell developers / authors what is wrong and what should be fixed.
Steam support team members behave arrogantly from time to time and I honestly don't like them much, but they at least respond when asked something.
Somewhere else surprisingly does none of those and therefore I don't recommend it, and it doesn't recommend my works either. And a bonus, a lot of trolls are there.