Approx. 6MB is for images. Pngs use rgba mode, so 4Bytes per pixel.
I can recommend to draw antialiased lines instead of loading pictures. Recommendation: at least load image one by one - one image at each program iteration, so the GUI is not blocked. Graphics looks nice you will need to make it fit also 480x480 screen
I faced challenges with limitations on number of files.
I a not loading the files in the loop, and just once at first startup.
The filesize don't seem to be an issue, but file numbers only.
I have made 1 workaround. I am layering 3 images.
-Front image with transparent area
-small Image for the scale that I move using XY coordinates
-Background
By using this technique, I am only using 2 small images to produce "good looking" graphics, instead of 10 or 20.
When it comes to 480x480, I agree... SADLY, I am not expecting to see any Jeti hitting the US market with 480x480 resolution in near future. I will consider it when the DS-24 V2 is available in US..