>>63867801there's a couple of lines where you add it so you can post and save soundposts without being affected by the filename randomizer.
Open 4chan X in the editor (assuming you have the greasemonkey or another editable version), and replace the line
if (Conf['Randomize Filename'] &&
g.BOARD.ID !== 'f') {
with
if (Conf['Randomize Filename'] &&
g.BOARD.ID !== 'f' && !(/(.*\[sound=.+)/g.test(
this.file.name))) {
