Massive fan of age and congrats on its success!! On size padding, I know you've patiently listened to me before on this, but I'll always take a chance to advocate for an approach like PURBs ( https://petsymposium.org/2019/files/papers/issue4/popets-201... ).

Let's say you're in a country that suppresses certain material, like copies of the Bible, or the Hacker Manifesto, or whatever; if the authorities find an encrypted file that closely matches the size of that material; that could do you in. But maybe a more realistic case is how the size of maps tiles alone is enough to figure out where you are looking on a map (https://ioactive.com/ssl-traffic-analysis-on-google-maps/), or the size of streaming video segments (https://www.cs.cornell.edu/~shmat/shmat_usenix17.pdf) gives away what you are watching. Both real-world examples of size side-channels. It's not un-imaginable that someone could use a tool like age to build bigger systems like that, where the leaks creep in.