Darkness is still wonky and awful as of Patch 8, but I have noticed that a warlock with the Devil's Sight invocation is immune to the blinding effect (creatures with natural superior darkvision aren't, though, for whatever reason).
The biggest problem that still persists with every surface-spawning spell (Grease, Spike Growth, Entangle and so on) is that the surface they create gets overriden with other things, like blood or water. There should be a priority order for surfaces overriding one another (anything that needs to be concentrated on shouldn't just disappear from being peed on, always staying on top of the other ones), and it should be limited to elemental interactions only (fire burning entangle vines/webs/grease, for instance).
