AE Colorspace Working space 'none'

Hi!

I'm trying to figure out how to solve color issues we encounter during a RED (R3D) workflow through After Effects. I hope someone can shine some light on this.
We have interpretted the R3D inside AE 2017 with the RED importer (interpret footage > more options) as follows:

- colorspace: Dragoncolor2

- gamma: REDgamma4

- rest as default, only the ISO as shot.

We have left the AE working space to 'none', as we usually use OCIO to manage colors to know what happens. Though we mostly do some removal work on this footage, so we won't need much color changes. 

The project is set to 32bit and we render image sequences to 16-bit EXR's with preserveRGB enabled.

At our end, everything works as expected. However, the grading facility had trouble getting enough color information from the EXR's.

Of course, you lose some dynamic range from the raw file when importing them with these settings. But I find it very strange that they claim the available colorgamut is sRGB, not DragonColor2.

So, what I would like to know is what happens under the hood when the After Effects colormanagement is set to none. Is must operate in some colorspace, it just should convert any colors if you don't want it to.
Or is this a known issue with the RED importer perhaps? How would we avoid losing color information from the R3D?