I only agree with just having another tier to let people know that Fujino might need more money. So I would see it as me donating/investing because I'm happy of what they do. But I kind of agree with kinglion, that I don't want any extra release thing attached to a higher tier. It alienates people, and that's not really a good thing.
If you're suggesting this idea because you're making an assumption that more income would allow Fujino to not work their day job, then I don't know. Usually for patreon, shouldn't you create a total monthly income goal/progress bar to indicate this? Like if he can achieve x amount from monthly payments then he'll be able to quit his job kind of situation. But also I don't know if Fujino is allowed to quit their job even if they have a lot of extra income. I don't know anything about Japan, but I wouldn't be surprised if Fujino has some extra issues or problems to deal with by moving to Japan from China. Like if Fujino needs to keep a job to have access to a green card to stay there, then it is what it is, and there's not much to be done about it?