Now if you don’t mind 8bit, quicktime’s png is smaller than animation’s for the same quality, but for 16bpc…
I have done a lot of tests and the smallest, free way to go is Tiff 16 bits trillions LZW off. PSD works too but is a little bigger.
PNG’s use lzw compression and so are 99.9% ok. Tga is not recommended either.
You can also buy cineform 444 and use prores 444 10 bit. Always use color management and 16,32 bpc in your projects imho.
https://technicolorsoftware.hostzi.com/