Hi @timmy, good catch!

There are some weird technical reasons for this that I won't bore you with but here are alternative ways to turn the image black and white that WILL translate to LUTs and Lightroom Profiles:

• Move the Spatial Volume tool all the way to the left.
• Move the Density, Vibrance or Saturation Curve points all the way to the bottom

The odd behaviour that the BW button isn't captured by the LUT/profile is due to optimizations of the internal render pipeline.

This pipeline is getting a major upgrade soon and that will also alleviate this behaviour.