Here's a small mod with a room recreating the classic "Icon of Sin" boss battle from Doom II. Cubes containing monsters will shoot towards you and the only way to stop them is to shoot missiles at a gargoyle trap faceplate with Nicholas Vining's head behind it.
Bohandas never said it's impossible to add custom sounds It's just not possible with the provided modding system, i.e. overwriting core files makes it impossible to Steam Workshop your mod
But we really should. It would be nice to have some kind of support for added sound effects, music, and altered core mechanics. Not to mention total conversion.
I'm along with you. But nearly none had tested the new conversion feature when Nicholas asked for it. (I tested it. It's not working.) Meanwhile, altering files is as easy as everyone can do it.