I like the way you think, but ultimately, whatever solution is adopted needs to be user friendly enough for the average joe to use it. Also I'm a little too preoccupied right now to even imagine being part of an initiative to create a new payment method for NSFW artiest. Best I can do is offer my best wishes.
Thankfully getting funding is not a life or death situation as I still have the day job. SubscribeStar seems to still be a reliable alternative (for now) as The Arcadean (Author of Corrupted Kingdoms) managed to get most of their supporters to migrate there after getting shut down on Patreon. I suspect Pixiv is probably going to have another solution before anyone else, but who knows.
This whole journey has been an interesting learning experience for me. I never realized and took it for granted, but NSFW artiest don't ever seem to get a break.
From crazy hypocrites, to the people of faith who are very much against sensationalizing boobs (even of the fictitious illustrated kind), to outright sanctions pushed by governments and payment processors, there are definitely hurdles to overcome. I'm beginning to realize why most people good at game dev stick to SFW, and why we only usually see high quality NSFW games come only out of Japan (where NSFW content is generally respected or at minimum, tolerated).
Regardless, I'm still working to get the next release out and push it to itch. The worse that happens is this game goes on hiatus and I start working on the farming sim that this project is based off of. If things improve I can always go back to this game and make the NSFW portion of the farming sim.
Anyway, sorry for the wall-o-text. Suffice to say I have a lot on my mind.