Runtime Quality Setting Changes for Sprites

I’m making a 2D game with Sprites. Obviously 2D sprites have no need for mip levels, however I have some large sprite sheets and I’d like to support older iOS devices (3GS, iPad 1, iPod 4) which all have a paltry 256 MB of ram. Setting QualitySettings.masterTextureLimit to 1 does nothing and I assume it is due to the fact that the textures don’t use mipmaps.

Is there a 2D way for QualitySettings to halve the textures in memory or do I have to come up with something else?

I have this same question. @derek9975, did you ever get this answered (5 years ago!)?