How the chatbox visually looks, and how the player interacts with it has not changed much over the years. Command lines are shoehorned into the same functionality. WIth jj2+ becoming bigger and bigger and with more commands and shortcut oddities, it can get quite daunting. Here's a list of quality of life ideas:

Prefix and colouring
Starting off the chat box with "/" changes the prefix "Chat:" to "Command:" and changes the prefix, chatbox to yellow.It can be backspaced to return to regular "Chat:"
- Starting off the chatbox with ">" changes the prefix "Chat:" to "Admin Chat:" and changes the prefix, chatbox and sent chat to green. Unlike commands, also removes the ">" from the typed box. It can be backspaced to return to regular "Chat:"
- Starting off the chatbox and chat with "/me" changes the prefix "Chat:" to "#[Playername]" and changes the prefix, chatbox and sent chat (This latter one already the case) to lightblue. Unlike commands, also removes the "/me" from the typed box. It can be backspaced to return to regular "Chat:"

Autocomplete for commands.
Commands can be difficult to remember. The current chat box is 1 line, and last chat of 8 lines above it. When starting Chat with / to start your command, moves the 8 lines of last chat up-to 5 upwards to show 5 autocomplete answers, alphabetically on available answers left. So it should look something like this:

Player1: Hey
Player2: Hey
Player1: How goes
Player2: Things go well
Player1: I'm testing the chatbox
||Player1 captured the flag
2 minutes left...
Player2: Cool
/addadminip <group> <ip_address>
/addallowedcommand <group> <command>
/addblockedcommand <group> <command>
/addprivilege <group> <privilege>
/admingroup <group> <on|off>
Command: /a

5 seconds later.....

Player2: Things go well
Player1: I'm testing the chatbox
||Player1 captured the flag
2 minutes left...
Player2: Cool
/allowready <on|off>
/allowmouseaim <on|off>
/allowsuicide <on|off>
/allowwalljump <on|off>
Command: /allow

5 seconds later.....

||Player1 captured the flag
2 minutes left...
Player2: Cool
/allowready <on|off> - Toggles the availability of the /ready command
Command: /allowr

So preferably when one command remains, it takes the description truncated to the first sentence.

Text scroll
Modernize the chat by scrolling chat into line position. From the 8 lines fade in the bottom line as it scrolls in, fade out the bottom line as it scrolls away (fading for 16-bit only, probably). Move as a whole. Scrollspeed around 0.4s per line lock.

Miscellaneous
- Move !swap to a /swap me command. Currently it's the only plus command that is in the "!" command. Would be better to not have that for consistency and let mutators fiddle with the "!" prefix.
- More to come eventually when there's ideas....