I would like to use my laptop for note taking in class, and use an android based e-ink tablet for handwriting and diagrams. What are your recommendations for delivering the tablet's notes to the vault?
Obsidian on the tablet with first party sync looks like a possibility. What about another app that can use SyncThing or similar that the laptop vault can turn pull?
I use git to synchronise and versionise my notes across my desktop pc and laptop. If I need access to the notes away from those two I simply access my git repository I self-hosted via gitea. Sure it has not the linking features of obsidian, but I still can read and edit the markdown files :)
My use case by the way is world building for a literature project and running Pathfinder Role-playing games.
I do the same thing, using a home-grown Git sync solution to keep my vault synced between my desktop, laptop, and Android phone. Free, and easy to setup on the computers, needed some additional SW on the Android side to get the sync to work.