I have a Sony A7RII that was converted to monochrome that I can use for infrared or normal black and white photography. The Bayer filter array was removed, so it should have increased resolution. There is a Windows programs called Monochrome2DNG that processes the raw files and creates a monochrome DNG file that I can open in either Lightroom or Raw Therapee, but I would prefer to use PhotoLab as I do for color images.
It would be great if you could support reading these DNG files.
I would be happy to supply sample files if you need them.
Digital Light & Color