My TV does DV, but is limited to 30Hz for DV over HDMI (don't ask me why) so I never really use it on my Shield. If I really want DV I use the app on the TV which means I can't use Ambilight anyway. But to answer your question: I have not tested DV material. The grabber shows up as support for HDR10/HLG only, so no DV. Might work with the EDID Emulator in between, but again, I have not tested this and am not using this right now.
I can do a quick test later today or tomorrow if you want
Yes, my TV with Shield TV is limited the same. But since Netflix provides DV just with 24Hz it doesn't matter. Still, I want to get Ambilight working there as well, so I would really appreciate if you could test it in the coming days 
So far it seems to me that this could be a much cheaper way to get HDR/DV done in comparison to buying the HDFury Diva.
There will be still the problem with the settings on RaspPi/Hyperion for changing to HDR/DV, but this is a problem for later 