I think that Lemmy Gold, Silver & Bronze are inevitable, with say a 90/10 cut to instance/lemmy-devs.
It would be best if the developers and the biggest instances agree on a standard payment system to implement into the Lemmy UI.
I’ve already donated to my instance as it’s a regional one, I didn’t buy Reddit Gold, but Lemmy Gold/Silver/Bronze is appealing to me given the money goes to a much smaller local group.