I might miss your target, but have you considered tasks.org android app + caldav?
I have been using silverbullet the last few months, but I struggle keeping up with its updates (too bleeding edge at the moment). I has a lot of nice features like all markdown, queries and templates.
Now I am back to tasks.org app + radicale self-hosted caldav server. For tasks it flows so well on android. for windows you need to use something that supports caldav, like thunderbird.
When silverbullet matures and if it is still fast and offline, I might go back. It has a lot of nice stuff going on. I still use for stuff like recipes and travel lists