I know this is a controversial topic, but I think Lower needs a bit of a change to make it good. I think there are two options.
Either it needs to get its free PvP status back.
Or it needs some NPCs who can actually influence PvP.
I play at times when there often is no DM on, or when there is one, he is busy. Since the PvP roll back, there have been numerous awkward conversations where people should be fighting, but suddenly aren’t. I have seen recent muggers walk around with impunity while their victims can do nothing. I have seen fights from the tunnels stop because one party runs up an ally into an almost empty shady alleyway. I have seen it used as an excuse to annoy players by taunting them knowing there is no recourse to violence.
What is even more frustrating for me, is when you finally actually get a DM, they don't add anything. The most that is done is to possess a beggar and provide a bit of combat commentary.
Since PvP is allowed elsewhere without restriction, and since no one in Lower seems to do anything to change a fight, it seems silly not to be able to fight there when no DM is on. I think the current situation is breaking my suspicion of disbelief as a player, and waters down the feel of Lower, which is now often safer than it should be.
If there is a strong desire from the DM team not to have PvP without a DM, make an IG reason. Even if the gangs are all weak due to IG actions, there must be a steady influx of hard men who were slaves. Have a few stand around on the corners, who can chip into a melee as the DM sees fit.