I haven’t used snap, so unfortunately can’t be of help there. FWIW, since Obsidian works fine out of the box following Solene’s flatpak guide, thought I should at least point that out. Even easier is Zim, which is available in the Debian repos. I doesn’t have all the bells and whistles that Obsidian add-ons provide, but that also means there’s zero vendor lock-in as well.