You only need to connect the Virgin hub directly to the TV to use any inbuilt SMART features.
The V6 connection to the TV has to be HDMI to HDMI. You can convert HDMI to Ethernet, but you have to convert it back to HDMI before it goes into the TV, which is a bit pointless.
For copy protection reasons there are no apps on TV's to allow the output from the V6 to be fed directly by Ethernet. It would also allow customers to feed additional TV's & avoid paying for Multiroom.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV6), Talk Anytime Phone, VIVID 350, Virgin PAYG Mobile
No and no device I know of currently takes advantage of HDMI's ethernet channel. Manufacturers avoid utilising this feature because of the limited bandwidth the ethernet channel has available to it. Because of this, you'd more than likely still want to use a direct ethernet connection to the V6 even if it had HDMI ethernet channel capabilities. Besides which, both your TV and the V6 would need HDMI ethernet capabilities in order to utilise this feature.
If trying to cut down the cabling then maybe consider disconnecting the V6's ethernet connection and using the box's wifi capabilities instead? The associated settings for this only become available if the box hasn't an ethernet cable attached to it.