How do I sync settings from one image to other images without having to save a preset and reapply that to all the images?
Simply put, you just copy and paste them with these simple steps.
1. Select the image in the batch pane with the setting you want to copy
2. Press Cmd or Ctrl - C to copy the setting of that image.
3. Press Cmd or Ctrl - A to select all the images in the batch
3a. You can also use other methods like Cmd/Ctrl-Click to select individual images from the batch
4. Press Cmd or Ctrl - V to paste the settings to the other images in the batch. The result will look like this, and it happens instantly.
Notice how the selected images now have the B&W setting applied by pasting the original setting to them, leaving the unselected images still in color. This can be done with any setting, not just B&W.
That's all you need to do to "sync" settings from one image to another.