How To Resize A Sprite Sheet/atlas Within The Editor, Without Losing The Individual Sprites

Hi,
So I'm working on an android game and rendering is taking a lot of time. I want to resize my sprite atlases and make them smaller, but the thing is, they're tightly packed and can't be divided up using any of the automatic options so resizing them outside the editor is going to add a lot of overhead, on account of me having to do divide the sprite atlases and then redo hundreds of animations. I'm looking for some way, a plugin, and asset or anything, that would let me resize the sprites inside the editor, while maintaining all the metadata and divisions for individual sprites. Any help is appreciated. Thanks!

 

Wait how is rendering taking lots of time if you have a few batch calls using a sprite atlas?

 

I figure the sprites are too big? I have 6 sprite atlases in total, the biggest one is 7 mb, 4096x4096 resolution. I used the profiler and the biggest amount of time was wasting in rendering. About 70% of the time was in gfx.waitforpresent. I understand it means the amount of time it has to wait for the past frame to finish rendering. What other reasons could there be, if not large sprite sizes? I'm not too sure.