Unfortunately my personal search for the same has left me with 2 conclusions:
Android is terrible for this. Most ergonomic way is to use Orgro or something as read only, and if read-only is not an option, then use an the full Emacs port for android (available on f-droid) which cones with its own input-related challenges.
Ultimately what is going to work is getting something like GPD Micro, a small machine with dedicated keyboard. Anything short of that is going to fail one way or another.
it seems to be easy and seamless to use org-roam with md-roam, and use obsidian on mobile and emacs on your real computer. I might update this post with more details once I tried it.