Someone going jungle just end up ruining the game, it's impossible to lane 1vs2 in URF. I don't understand people doing it, URF is about facing off against real players while spamming abilities not about spamming them on jungle monsters. I don't how if that is really fun especially when you leave a teammate suffering alone and sometimes can't even play safe under tower and keep dying.
I can understand picking smite as a legit summoner spell for dragon and baron but you need to go in lane, so either disable smite or leave it and disable jungle items. But I'm sure some people will still go jungle just cause they have smite even without jungle items, so maybe delay the spawn of the jungle monsters in early game just as the laning phase sets over.