I got Blender plugin and honestly think it doesn't make any essential convenience over just stand alone. It's always " no render server" or any other quirk, no proper ID passes etc.
Most annoying thing is it takes forever to start the rendering itself after any geometry related tweak so not that much real time visual feedback you could expect.
So I use standalone anyway.
Tried demo version for 3d max and also had mostly same problems plus another set of quirks.
So I wonder with what 3d package Octane is integrated the best way, having speedier real time connection, working baking features etc ?