Roku support DD+ Atmos, not TrueHD Atmos. That is a Roku limitation.
We are not aware of DTS issues other than the newer Roku Ultra 4800, which causes a stutter during Direct Play (roku firmware issue). This model seems to have a few quirks. We are notifying Roku about the various issue, but those will need to be fixed at the firmware level.
DV is supported on Roku TVs with DV, as well as the new Ultra 4800. Also note that not all DV is the same, so you may need to handle cf. [FEATURE REQUEST] Dolby Vision support for MKV (ROKU TV) - #11 by Theridges
