I used the search function, but I couldn't find anything related to this. I believe it's currently an admin option to automatically display the additional options when posting a new topic. Some users prefer to have them collapsed by default, while other users prefer to have them expanded instead. It's not really a big deal, but if there's an admin option for it, I don't see any reason why it can't be added as user option. :)
To be honest, I have no idea how user options work so I can't write some code to do this myself.
Interesting. I also find it a little bit hard to do specific search without the options like the admin has.
Having it as a user option is more overhead (just so you're aware of that).
The overhead is not significant actually. If the default is adhered to, it's a single extra row in the themes table per theme (versus one row total in the settings table), plus one row for every non-default value.
There's already enough fluff that it's not likely to be made much worse.
Tracked https://github.com/elkarte/Elkarte/issues/220