When rendering in Karma with Aces i always have the feeling that my blacks are getting super crushed using the ACES SDR Video Tonmeapping. Last few years working with Redshift I never experienced this behaviour. Not sure if this is intended.

Aces 1.0 SDR Video is a tonemapped view transform that definitely applies a contrast curve that seems to crush the black and boost the whites, but it seems consistent with the way Nuke applies the view transform as well. You can switch to "un-tone-mapped" if you want no tonemapping. There's another post recently where jsmack describes how to edit your ocio config to change the default view transform if you'd prefer "un-tone-mapped" to be default.