Load a folder of images & apply various general adj on each one in a thumbnail mode & when done save all in one go in a folder or whatever...
CTRL-Drag an image to next 'split' to get a copy to further edit for variance...
Fast & cool for this kinda need...
NOT A THUMBNAILER! You are processing the FULL images just in a smaller image size!
https://www.cockos.com/snapease/
