Minor request: could the source column show label color and/or tag icon for each folder, perhaps by coloring the folders and placing the tag icons next to each folder?
Showing the label color in the source list is on my to-do list. I’m not sure that this would really work for tags, since there might be many tags assigned. However, you can set the icon for each folder using the Finder’s Get Info window.
EagleFiler 1.2.4 shows labels in the source list (the same way it shows them in the records list).