well, we can limit to 64k instead of 64 pixels
reaching 1mb is already difficult if the limit per icon size is 64k
it looks soooooo beautiful without the limitation 
edit: i think you’re quite right, 64 seems enough.
through investigation i could notice that most icons are 32x32
but i ask you to consider giving room to 64 bit variables, since our modern computers can handle it just fine, you calculated for 32 bits and it was pretty good, but i bet we can do 64 bits without raising a lot of memory consumption, i bet everyone has 2mb of memory to spare, and it’s not even going to reach 1mb if there’s only a few dictionaries…