splashing some dimir surveil action with golgari undergrowth is very nice. prob good the other way round too.
Dimir's creatures tend to be high impact and the payoffs for Undergrowth tend to not last beyond the turn. If Golgari were Izzet or Boros that wouldn't be as much of a problem, but it's not. I definitely don't think Surveil splashing Undergrowth is deece.
As for why I didn't try a blue / black / green deck, I had two copies of Watcher in the Mist, two copies of Deadly Visit, the aforementioned Nightveil Predator, an Izoni, Thousand-Eyed, a Beast Whisperer, a Hatchery Spider, two copies of Generous Stray and a Dimir Spybug. Those are two different decks' worth of cards. Typing that out pisses me off at myself for not playing Golgari, smgdh.
On a tangential note, I also don't think Surveil and Jump-start play particularly well together either. With an exception or two you want to cast the Jump-start cards twice because they're actually balanced. If you have to bin one it's not the end of the world but it's also not particularly great either.