Playeble without George Romero mod, but there won't be tank on finale
I tested without George Romero mod, & it worked without crash even with 50+ script mods (no idea about other mods, but at least some script mods won't cause crash). Without that mod, special infected can still spawn, though tank & witch spawns will be completely up to Director. However, without George Romero mod, there won't be tank on the finale, so only special & common will come in several waves until the rescue unit is ready. So in short, it's playable. Some areas have RE campaign vibes. There are some missions about collecting items/ keys & scavenge event, though the scavenge event is pretty tiring as the gascans are scattered at far locations.
Like the title, it's a pure torture if played without cheats