Documentation is the same as other platforms: Keyboard shortcut reference - Dynalist Help Center
Because iOS intercepts many shortcuts, some of them are not working. Tab, Shift+Tab, Up, and Down are all cases that were intercepted by the iOS system.
More complicated shortcuts like Ctrl+Shift+M to move should always work.
And yeah, what @joegnis said, if the zoom in/out shortcuts are important to you, I’d appreciate it if you could open a new topic on it 