well, first of all it would be nice if there was, yknow, actual moderation and anti-harassment features and maybe slightly less inline security vulnerabilities, but aside from that it's mostly just quality of life stuff.
- soft navigation
- popovers for stuff that shouldn't only be an entirely separate page (like notifications and comments)
- a better setup for CSS color variables. the current system is confusing and variables only adapt to your system color and not the actual light/dark post themes
- follower count. i've been here since 2022 i'm allowed to say that not having one is stupid
- literally any sort of "notes" system for at least your own posts. interaction is what drives a social media site and stifling it in the name of anti-clout or whatever is lame
- a better notification system. i took one in-depth look at how the api groups notifications together and it made me want to tear my fur out
- a "copy link" button. i saw someone suggested this on the forum and it immediately got shot down, but like come on. how many people not used to tumblr would've known that you can copy permalinks from the timestamps. that's just hostile design
that's just the gist of what i can remember offhand without consulting my design document but yeah
