Out of curiosity, why is Obsidian closed source? It doesn't look like you charge for anything, and with the size and type of following you have, you'd probably see some really cool stuff get sent your way.
I realize they are just markdown files, but they use a proprietary "Obsidian" markup that will require painful conversion if I ever need move to another app. I've been through this before and it has always been a massive headache.