A very useful improvement would be to make it possible to search for all the messages of a particular person. I recently saw a message that I wanted to pay particular attention to, but didn't have the time for that in the moment. Then maybe a couple of weeks went by. Now I have no way of finding it that wouldn't be very time-consuming.
The present search function includes "Posted by (handle)", but entering something in the "Search for" box is mandatory. I tried several words, such as "the", that would be found in any message, but that didn't work.
Another forum in which I participate, on groups.io, provides this via clicking on the handle of any message. I.e. if you want to see all my messages here, you would just click on "Philippa Strahm" at the beginning of this message.