I cannot say about cancelling the support, as far as I can recall, only one person told me explicitly that if there was no incest patch he would not play the game at all.For those who don't like incest, it really doesn't matter if the game has an incest patch or not, this is obvious, however there are many users who insist on playing with the patch. And I would even say that some supporters would go as far as to cancel their support if the incest was missing (patch)
The one thing that I can say is that there are 312 (313, but don't consider the one from Zorlun) "likes" to the post with the incest patch link, which even if for some people are just like "solidarity/moral support" likes and we cut in half, means there would be 151 people using it, or at least having used, it (plus myself).
For the ones that do not like the incest, well, remember the game has to cover as many possibilities as possible (putting aside Patreon's intervention), and it is only a game, not reality, and actually you can play the game without ever seeing it.
Effectively, even if I created the patch and maintain it, I myself do not like the path there were Myriam is dominant towards Marc, because makes me think to my idea of incest being most often an adult that takes advantage of a younger one , but nontheless I keep it active in the patch, because not everybody has my likes and dislikes, it is only a game, and it was in the original game.