I made some changes to Drox 12x12 and the 3x4 hot bars there smaller than the originals.
you only need to open the window folder in drox and copy the file into the folder.
Always make sure you back up the original file before you add these in case you want to revert back to the original window

I was unable to figure out how to scale the fronts down to fit in the smaller boxes when making a hot key. If any one know how please let me know thanks

Credit:
Drox
Craeat