What do you want to see in a .lvl mod?

[MileHighGuy]

So I'm making a smallish mod that currently replaces some side lvls and the common.lvl. I made some effects look better and did some subtle cosmetic stuff. I also enabled the free camera and did phobos's exit to windows multiplayer crash fix. I want to include the things the community has made

Are there any other "breakthroughs" by the community that I should include in my mod? Things with the core.lvl or mission.lvl too? It has to be multiplayer compatible.