Thumbnails to Ext SD Card??

If you have a lot of photos on your device, the gallery view thumbnails seem to use a tremendous amount of data; - nearly 2 gb on mine!! I have used utilities that allow me to clean these to retrieve the space, but the next time I view the gallery, the thumbnails just take up the space again; in addition, the performed task of cleaning them out just makes them load more slowly.

I'm hoping someone may have a trick (or hack) that can move the gallery thumbnails to the external SD card. Considering I only have 16gb of storage to begin with, and nearly 5 of it used up to store the basic OS, I'm not left with much space after installing my favorite apps. Furthermore, the performance on my device seems to be degrading as I approach maximum storage capacity on the internal storage.

I'm aware of programs that allow me to move program data to the external SD, but I have found that it's not uncommon that many programs have a tendency to glitch when using these utilities. I'm really more interested in staying focused on my primary intent of moving JUST the gallery thumbnails to the external SD card in hopes of saving space on my primary storage.

If it matters, my device is a rooted Verizon S5 running KitKat 4.4.4.