I hoped side-by-side view (two docs in two panels at the same time) exists, looked for it by rightclicking on the tabs and looking for the option a la Obsidian.

Nope, you have to drag it! That decides h/v orientation. Neat.

This works in Obsidian too!

EDIT: SAME NOTEBOOK IN TWO TABS IS CALLED “View”, not available through that menu, because why not