I'd absolutely love heavy bombers, but even if someone makes a gargantuan Kashan Desert-style map, I don't think there'd be room for them
. So I guess if you want them in, you'd have to think outside of the box.
You could have them as a squad leader/commander deployed asset, though. The First Strike team made a system that had a fighter jet overfly the map and drop bombs on targets you designated. It's on YouTube somewhere, and if you search "First Strike", you'll probably come across it.