No, by roaming Internet and visiting forums and publishing sites.
I can describe my way to F95 throw the finding one of the games, but that will be not about the Witch Hunter Trainer, so I decide not to put this story here.
May you recommend some of these forums and publishing sites?
As for the state of this game, its inexcusable. I understand that Adult Games is still a very niche market here in the West and as such most western projects depend on either fan contributions or creators making games because they want to. I've always personally supported any games I liked, even if I found them here. I was a Patreon supporter for this game for a long time, but at a certain point a Dev needs to be open with the state of the game.
I really do believe that if a Dev is starting to significantly slack in updates and quality of the game, the natural and NEEDED response is to stop supporting them financially, this will force the Dev to either develop the game as promised for their backers or lose their income, which a lot of these 'non-first-world' Devs can live very comfortably on alone. Often times I give Devs at least a year before I pull my support, so at this point I'd be pleasantly surprised if we saw anything of note with this game and others like it.