Hi Daniel,
thanks for the answer. Regarding the interaction, I’ve also written Ken directly, and I think its an open issue. Would be great to have the possibility to snap all objects together and interact with them as a whole. The slicing also does not affect any volume rendered objects yet. I am sure that they are working on this, and just thought maybe I haven’t found that magic switch. 
And Regarding the Linux thing: Sorry, I got your name mixed up. I asked for help in another thread regarding building and running OpenVR under Linux (OpenVR under Linux) and I was to quick to read Cory’s answer there, and thought that the person he suggested to ask would be you. Sorry for this.
Are you building ParaView and OpenVR under Windows10 yourself, or are you using the pre compiled VR binary?
Cheers,
Niklas