Oh, hell yes. The more features that can be controlled by players (in customs) the better. Icing on this settings cake would be the ability to control which boosters (& levels) and guns (& their mods) are used by each team. Being able to choose rounds of co-op to start a game on would be cool as well- no more slogging through the first couple of rounds- just go right into the action!
It may be a little late for ND to implement these ideas, but these ideas must be at the very least considered for UC4.
Co-op Adventure Tips & Tricks and Amazing Lab Idea- Now with Brackets Mentioning Kudos Count!