I know this seems trivial so maybe easy to implement, but navigating through multiple open images with ctrl-tab makes workflow a lot easier.

Likewise ctrl-f4 to close images is especially handy when they aren't maximized but the buttons, or even the whole title bar, are invisible off the edge of the screen. Alternative hotkey would be ctrl-w like Adobe uses.

Currently ctrl-tab has funky results, it cycles to last frame while focusing on something else, so the hook needs cleanup either way.