Wait, so they can activate the game on their german Steam account without any problems? Without needing to use VPN or something similar? In that case, I'd try joining the patreon within the next couple of days.
Because for what it's worth, I don't have any problem inherently with using Steam, I use it all the time, it's just very problematic for any kind of adult game these last few years. But if the game can be activated without any problem on a german account, then there might still be a chance for me.