Honestly the risk of procedural generation of large cities being bland is a very minor issue, that could easily be counted by having the main grid road system pass first, then the zone tiles placed, but also add PG to each individual tile itself on the final pass. or even just have many variations of sub roads and tile types.
if you can go in once the build is finished and regenerate each tile independently it would be extremely flexible.
for now I would just settle for the actual city and road system without interior rooms as the game type I would like this for is a vr cockpit flight game.
this would help small teams and solo devs like me get a real jump in getting games off the ground. But as of yet I have not come across anything in the ue4 marketplace even like this. Yet I have seen something like this in the unity store 