It's interesting to read the discussion about Sixel support in Kitty [1], where the pros and cons of Sixel are considered in relationship with Kitty. In particular, I find this comment [2] by the maintainer of libsixel particularly intriguing:
> After I took over the maintainership of libsixel I unfortunately decided it cannot support the security demands of Kitty, it is too insecure internally. I need to write a Rust library or something.