I'd just like to see heavy spawns reverted to D1 standards across all playlists. Once per match, if you're at the chest when it opens, you get some. I've never liked the heavy system in D2.
For Control and Clash, I agree. For those 6v6 modes, its too unpredictable as to when you'll run into someone with heavy. So its almost impossible to manage such encounters. But for 3v3? No. Without some sort of objective, you'd never get people out of their spawns....and the pace of play would grind to a halt.