The / button in chat is pretty useless. It offers a faster way to enter only a select few commands and they aren't particularly long or complex ones either.
It would be much more useful and convenient if you could type in a command and bookmark it there. If you have a command you use a lot for whatever reason, you could bookmark it and easily re-use it. I feel like this would be particularly helpful for map makers, who often need to use long and complicated commands repeatedly.
Additionally, a feature that allows you to organize your saved commands in the same way the default / options are organized, with a list of variations of the same base command scrolling out when it's selected, would be nice.