Thanks for that quick implementation! Cool that I could get a hands on experience soo quickly!
GC already has some great features for comparative multi image viewing
• Menu > Window > Arrange > Cascade ⌘ ⇧ 1 | Tiled ⌘ ⇧ 2 | Horizontal | Vertical
• Plus tweaking at: Preferences > General > Display Screens > Arrange Windows: [√] Limit to screen: Select screen in your multiscreen setup.
• ⌥ click on the "Show/hide toolbar" button applies this to all windows! Then just do another ⌘ ⇧ 2 to re-arrange without the gaps/overlaps.
• And now the possibility to change zoom for all windows at once.
: In build 5636 the viewport adaptation happens to all windows BUT the current window.
: The viewport adaptation should happen to ALL windows, that includes the current window.
• This makes sense as you want to "synchronize" between all windows to have your glance at the same area, or in case of windows on top of each other using prev/next window shall have the content perfectly aligned, your current window including.
• It's odd if your current window is the only "outlier".
I also have a problem to assign shortcuts as I want, see: Edit Shortcuts: Cannot assign shortcut combo CTRL plus letter
When that's fixed I will be able to work much faster with this new zooming. Then further feedback regarding zooming will come.