Hey, apologies for the late response I was gone for a while.
I got the unit now and can confirm that the Bolt v2 does not play with the Bontrager lights.
I am wondering about your experience with the Bolt and Varia, I noted that when I am riding along and then turn the Varia on (I only use it when it's needed due to the awful battery life, I have the non-light smaller unit) it does not automatically come up on the Bolt screen unless I click the top left side button on the Bolt to briefly go to the main menu, then when returning to my ride pages the radar strip will show up after a few seconds. Seems like the Bolt does not check for the Varia sensor until it's briefly on the menu page.
This was extremely frustrating, turning the unit on and off multiple times while riding, until I found the little menu page hack. But it's far from ideal still as I'd like to just reach back, turn the Varia on/off, and have the head unit respond without further trickery. Does yours work better? Firmwares are all up to date.
That's how my Varia works with Bolt v2. A little irritating, but not a dealbreaker. I can do it while riding along.