This is nice, it basically does what i asked a year ago[0] and at the time pretty much every solution wanted a litany of Python dependencies that i ended up failing to install because it took ages... and then i ran out of disk space.
No, really, this replaces literal gigabytes of disk space with just a 799KB binary. And as a bonus using the Q8_0 format (the one that seems to be the fastest) it also saves ~2.3GB of data too.
That said, it seems to be buggy with anything other than the default 512x512 image size. Some sizes (e.g. 544x544) tend to cause assert fails, sizes smaller than 512x512 (which i tried as 512x512 is quite slow on my PC) sometimes generate garbage (anything smaller than 384x384 seems to always do that).