Great list with options. I think more developers should opt for the Patreon. Eugen Rockho aka Gargron is making 3k with this for his Twitter alternative Mastodon @ https://www.patreon.com/mastodon. It is possible to fund a developer, but can you fund a whole company this way?

Liberapay is another platform, an open source Patreon alternative, also has a few funded developers and dev-ops like Technowix @ https://liberapay.com/Technowix/.