Welcome to Roon. I do not know of a tone within Roon. I personally used REW and made my adjustments on my amp. You can enact changes using a DSP setup within Roon that you make with your REW measurements for example:
Using REW+Roon/MiniDSP for extreme EQ - Tinkering - Roon Labs Community
There are a number.
I can not talk to the HDMI and Node question but think others here will.
Enjoy.