Could you explain a little more which part needed sanding down? Looking into trying it as well.
you have to sand down this pawl ring. Let the three pawls mounted and sand them, too.
Meanwhile I graded up to 12-speed Campagnolo and the Wahoo-hub fits that, too 
I have a Wahoo Kickr Core trainer and a 10speed Campagnolo bike. Bought the Wahoo Campi free hub, but had a VERY HARD time finding a Campi 10s cassette that would slide onto the hub. On the 3rd try I found the Campi Centaur 12-27 cassette is compatible - all cogs slide onto the hub. NOTE: Centaur 12-25 is NOT compatible (1 cog is 8-armed, rest are the needed 4-arm). I want to post this info where I can to save others the 3-month effort of finding a solution to using a 10s Campi bike on Wahoo Kickr Core.
Giving this a bump as it’s been a while since anyone has posted an update. Has anyone found a viable solution to setup Campy Ekar 13 speed with a Zwift Hub? I’m thinking my best bet is to use virtual shifting, but I still need to find a cog or freehub setup that will work.