Aces

[^Lele^]

When you get your raw data, it's just as likely maya threw an error and loaded no LUT at all (see my original gripes), or for whatever reason defaulted to a different one (one'd have to investigate in the config...) which allowed raw data through.
Even in the VFB, changing the input to data produces unclipped colors, so i'd be quite safe assuming is the view LUT itself.
I loaded the OCIO config in the maya color management prefs to, to little avail, as well.

[sharktacos]

When you get your raw data, it's just as likely maya threw an error and loaded no LUT at all (see my original gripes), or for whatever reason defaulted to a different one (one'd have to investigate in the config...) which allowed raw data through.
Even in the VFB, changing the input to data produces unclipped colors, so i'd be quite safe assuming is the view LUT itself.
I loaded the OCIO config in the maya color management prefs to, to little avail, as well.

In the images above I did not re-render, so the raw linear data is the same in both. The only difference is the view transform.

That means further that the issue is not with the render (Vray), but with the OCIO config.