When I used to use Reddit, one of my favorite things about it was the design of the navigation. Specifically I am referring to when you open a post, and the only thing needed to go back is to click in the margin.
Alexandrite also implements this same type of functionality.
If it hasn't been suggested already, I'd like to know if this is something that could be implemented here as well.
Assuming that kind of functionality involves JavaScript, it depends on how much it involves. From what I understand, PieFed is designed to be accessible in low resource / low bandwidth environments, which downloading megabytes of JS isn't compatible with.
It would probably need to get to the point of PieFed having an API, and then a front-end (with a design like Alexandrite) can use as much JS as it likes, because it's something the user has agreed to.