For instance, If a device accepts DSD512 or DSD 256 via USB input, and if this device is roon ready DOes this mean that ROON can send the device bitperfect dsd512 audio.
I know that OPPO cant do that, so I wonder if all devices have such limitations.
For instance can roon send bitperfect DSD128 to PSAUDIO direct stream dac
I’m not understanding the confusion sorry, Roon can send DSD 512 via USB to any DAC that can receive it, and via Ethernet to any Roon Ready DAC that can receive it.
Your question is about DSD capability of a device, not Roon Ready capability (as andybob said, Roon is always capable, whether the device is, is a matter for the device manufacturer, not Roon).