Please add a toggle somewhere to enable/disable chat sound effects (<se.1>)

This has mostly been an issue in PVP where players that do callouts insist on adding sound effects on their messages and proceed to press them 3-5 times per callout. My blacklist is full of almost exclusively these players because of the noise pollution they cause. I've run out of space on my blacklist, so I mostly just play the game with sound off when I PVP now.

*Danger bongos intensifies*

Sounds like you solved your problem.

Some of us appreciate the callout sounds. Some of us like to try and win. ;)

just disable system sounds in system configuration

There's a command to disable System sounds on the go: /systemsounds. Could disable it when entering a PvP match and enable with the same command.